Antiparasitic artemisinin derivatives (endoperoxides)

ABSTRACT

This invention relates to the use of certain C-10 substituted derivatives of artemisinin of general formula (I) in the treatment and/or prophylaxis of diseases caused by infection with a parasite, certain novel C-10 substitued derivatives of artemisinin, processes for their preparation and pharmaceutical compositions containing such C-10 substituted derivatives. The compounds are particularly effective in the treatment of malaria, neosporosis and coccidiosis.

This invention relates to the use of certain C-10 substitutedderivatives of artemisinin in the treatment and/or prophylaxis ofdiseases caused by infection with a parasite, certain novel C-10substituted derivatives of artemisinin, processes for their preparationand pharmaceutical compositions containing such C-10 substitutedderivatives.

Malaria is the most important human parasitic disease in the worldtoday. Approximately 270 million people throughout the world areinfected with malaria, with about 2 million dying each year. The abilityof parasites to produce a complex survival mechanism by expressingvariant antigens on the surface of infected erythrocytes makes itpossible for the parasites to escape from the destructive action of thehost immune response against these antigens. In addition, the increasingrate of malaria infection is due to the spread of chloroquine-resistantstrains of Plasmodium falciparum and the other multi-drug resistantstrains.

In the field of animal health, parasitic diseases are a major problem,especially those diseases which are functionally related to malaria. Forinstance, neosporosis is a term used to describe diseases caused byparasites of the species Neospora, especially Neospora caninum, inanimals. Neospora infections are known to occur in dogs, cattle, sheep,goats and horses.

The final host for Neospora spp., including Neospora caninum, is unknownand, in addition, the complete cycle of development of the parasite isnot understood. The asexual phases of reproduction, known as schizogony,and the behaviour of the unicellular tachyzoite/bradyzoite stage havebeen clarified, however. Tachyzoites are infectious unicellular parasitestages of about 3-7×1-5 mm in size formed after intracellularreproduction termed endodyogeny. Reproduction via tachyzoites takesplace preferentially in organelles such as muscle or nerve cells.Pathological symptoms invoked after an infection are associated mainlyin those tissues Some five to six weeks after natural infection in adog, symptoms of the disease are hypersensitivity caused by inflammationof neuronal cells and increasing tendency to hyperextension of the hindlegs. Histopathological lesions are apparent in the nervous system,preferentially in the brain and spinal cord. Extensive non-suppurativeinflammations, glial excrescences and perivascular infiltrations ofmononuclear cells (macrophages, lymphocytes, plasma cells) dominate, andare also partly apparent in eosinophils and neutrophils. In the muscularsystem, macroscopically observable necroses and degenerative changesappear. Apart from the more or less strongly developed atrophy, longpale longitudinal stripes are evident.

In California and Australia, Neospora caninum infections appear to bethe main cause for abortion in cattle. Symptoms of the disease in cattleare similar to those in the dog. Ataxia is apparent, joint reflexes areweakened and pareses at the hind legs, partly in all four legs, can beobserved. The histological picture is similar to that of the dog; mainlynon-suppurative meningitis and myelitis.

Data on in vivo activity of compounds suitable against neosporosis arerare because adequate in vivo test systems still have to be developed.Sulfadiazin (administered via drinking water) is effective inexperimentally infected mice, only if the treatment was prophylactic,that is, the treatment was started before infection. In dogs, treatmentwith sulfadiazin and clindamycin is only successful if it is startedearly, that is, at the appearance of first clinical symptoms as a resultof neuronal inflammation.

Coccidiosis, an infection of the small intestine, is relatively rarelydiagnosed in humans, where it is caused by Isospora belli. However,humans are also the final host of at least two cyst-forming coccidialspecies (Sarcocystis suihominis and S. bovihominis). Consumption of rawor inadequately cooked pork or beef containing such cysts can lead tosevere diarrhoea, the cause of which is probably seldom diagnosedcorrectly. Coccidia (phylum Apicomplexa, suborder Eimeriina) are one ofthe most successful groups of parasitic protozoans, having conqueredvirtually every class of Metazoa. The ones that are of particularimportance for man are the 60-100 species which parasitise domesticanimals and which in some instances can cause very severe losses,especially in poultry, although also in lambs, calves, piglets, rabbitsand other animals (see Table A). TABLE A Causatives of intestinalcoccidiosis in domestic animals number of Eimeria most pathogenic and/orand/or very common species Isospora (E = Eimeria, Animal species*) I =Isospora) chicken (Gallus gallus) 7 E. tenella, E. necatrix, E. maxima,E. acervulina turkey (Meleargidis 7 E. meleagrimitis, gallopavo) E.adenoides goose (Anser anser) 6 E. anseris, E. truncata, E. nocens, E.kotlani duck (Anas platyhynehus) 3 Tyzzeria perniciosa, E. anatis pigeon(Columba livia) 2 E. columbarum, E. labbeanea rabbit (Oryctolagus 11(12) E. intestinalis, cuniculus) E. flavescens, E. stiedai, E. magna, E.perforans sheep (Ovis arius) 11 (16) E. ovinoidalis, E. ashataE. ovinagoat (Capra hircus) 12 (15) E. ninakohlyakimovae, E. arloingi cattle(Bos taurus) 12 (15) E. zuernii, E. bovis, E. auburnensis pig (Susscofra)  7 (14) I. suis, E. debliecki, E. scabra dog (Canis familiaris)5 I. canis, I. (Cystisospora) burrowsi cat (Felis catus) 2 + 6 I. felis,I. rivolta as final host: Sarcocystis bovifelis, S. ovifelis, S.fusiformis, S. muris, S. cuniculi, Toxoplasma gondii*)regarding to Pellerdy (1974), Eckert et al, (1995b, Levine and Ivens(1970) and Mehlhorn 1988)

Most of the pathogenic species are strictly host-specific. They have acomplex life cycle with two asexual reproduction phases (schizogony ormerogony, and sporogony) and a sexual development phase (gametogony). Inview of the major importance of coccidiosis, numerous reviews areavailable, for instance, by Davies et al. (1963), Hammond and Long(1973), Long (1982, 1990), and Pellerdy (1974). The economicallyimportant species sometimes differ very considerably in theirsensitivity to medicinal active ingredients. The sensitivity of thedifferent developmental stages to medicinal agents also variesenormously.

As far as the use of drugs is concerned, prophylaxis is the mainapproach in poultry, in which symptoms do not appear until the phase ofincreased morbidity, and therapy is the principal strategy in mammals(McDougald 1982). Polyether antibiotics and sulfonamides, among otherdrugs, are currently used for such treatment and prophylaxis. However,drug-resistant strains of Eimeria have emerged and drug-resistance isnow a serious problem. New drugs are therefore urgently required. Giventhe multiplicity of pathogens and hosts, there is no “ideal model” foridentifying and testing anticoccidial agents. For example, most of themany substances used for preventing coccidiosis in poultry areinsufficiently effective or even completely ineffective againstmammalian coccidia (Haberkorn and Mundt; 1989; Haberkorn 1996). Numerousworks and sets of instructions have been published on testing of activeingredients in animals for anticoccidial efficacy, for immunisation,etc. One particularly important and comprehensive example is the surveyof current methods published by Eckert et al. (1995a)

The compound artemisinin, also known as qinghaosu (1), is a tetracyclic1,2,4-trioxane occurring in Artemisia annua. Artemisinin and itsderivatives dihydroartemisinin (2), artemether (3) and sodium artesunate(4) have been used for the treatment of malaria.

Different modes of action have been proposed by various groups toaccount for the action of artemisinin and its derivatives in treatingmalaria (Posner et al., J. Am. Chem. Soc. 1996, 118, 3537; Posner etal., J. Am. Chem. Soc. 1995, 117, 5885; Posner et al., J. Med. Chem.1995, 38, 2273). However, irrespective of actual mode of action, allcurrent derivatives suffer from poor oral bioavailability and poorstability (Meshnick et al., Parasitology Today 1996, 12, 79), especiallythe ‘first generation’ ethers and esters artemether and sodiumartesunate obtained from dihydroartemisinin. Extensive chemical studiescarried out on artemisinin and derivatives indicate that a cause ofinstability is the facile opening of the trioxane moiety in artemisininitself, or in the metabolite common to all currently used derivativesartemether, arteether and artesunate, namely dihydroartemisinin. Ringopening will provide the free hydroperoxide, which is susceptible toreduction. Removal of this group ensures destruction of drug activitywith the reduction products being transformed into desoxo metabolites.In order to render ring-opening less facile, the oxygen atom at C-10 canbe either removed to provide 10-deoxydihydroartemisinin, or replaced byother groups, and this has provided the basis for the so-called ‘secondgeneration’ compounds which are generally 10-deoxy artemisininderivatives. In addition, derivatives of artemisinin have also beenprepared with a variety of substituents at C-9.

Artemisinin derivatives are also known in which the oxygen atom at C-10has been replaced by an amine group. For instance, Yang et al (Biorg.Med. Chem. Lett., 1995, 5, 1791-1794) synthesised ten new artemisininderivatives in which the oxygen atom at C-10 was replaced by a group—NHAr where Ar represents a phenyl, 3-chlorophenyl, 4-chlorophenyl,3-bromophenyl, 4-bromophenyl, 4-iodophenyl, 4-methylphenyl,4-methoxyphenyl, 3-carboxylphenyl or 4-carboxylphenyl group. Thesecompounds were tested for in vivo activity against the K173 strain ofPlasmodium berghei and found to be active.

Whilst the current artemisinin derivatives are successful, there areproblems associated with stability, bioavailability and potentialneurotoxicity. There is also a need for artemisinin derivatives whichexhibit a broad spectrum of activity against a variety of parasites.

It has now been discovered that certain C-10 substituted derivatives ofartemisinin are effective in the treatment of diseases caused byinfection with a parasite. These compounds are particularly effective inthe treatment of diseases caused by infection with a parasite of thegenera Plasmodium, Neospora or Eimeria, especially Plasmodiumfalciparum, Neospora caninum and Eimeria tenella which cause malaria,neosporosis and coccidiosis respectively. According to the presentinvention there is therefore provided a compound of the general formulaI

or a salt thereof,

-   in which-   Y represents a halogen atom, an optionally substituted cycloalkyl,    aryl, C-linked heteroaryl or heterocyclylalkyl group or a group    —NR¹R²; where-   R¹ represents a hydrogen atom or an optionally substituted alkyl,    alkenyl or alkynyl group;-   R² represents an optionally substituted alkyl, alkenyl, alkynyl,    cycloalkyl, aryl or aralkyl group; or-   R¹ and R² together with the interjacent nitrogen atom represent an    optionally substituted heterocyclic group or an amino group derived    from an optionally substituted amino acid ester;-   for use in the treatment and/or prophylaxis of a disease caused by    infection with a parasite other than an organism of the genus    Plasmodium.

Suitable salts include acid addition salts and these may be formed byreaction of a suitable compound of formula I with a suitable acid, suchas an organic acid or a mineral acid. Acid addition salts formed byreaction with a mineral acid are particularly preferred, especiallysalts formed by reaction with hydrochloric or hydrobromic acid.Compounds of formula I in which Y represents a group —NR¹R² where R¹ andR² are as defined above are particularly suitable for the formation ofsuch acid addition salts.

Any alkyl, alkenyl or alkynyl group, unless otherwise specified, may belinear or branched and may contain up to 12, preferably up to 6, andespecially up to 4 carbon atoms. Preferred alkyl groups are methyl,ethyl, propyl and butyl. It is preferred that any alkenyl or alkynylgroup is not an alk-1-enyl or alk-1-ynyl group. In other words, thereshould preferably be at least one methylene group —CH₂— or similarsp³-hybridised centre between a carbon atom forming part of the doubleor triple C—C bond and the nitrogen atom to which the group is attached.Preferred alkenyl and alkynyl groups include propenyl, butenyl, propynyland butynyl groups. When an alkyl moiety forms part of another group,for example the alkyl moiety of an aralkyl group, it is preferred thatit contains up to 6, especially up to 4, carbon atoms. Preferred alkylmoieties are methyl and ethyl.

An aryl group may be any aromatic hydrocarbon group and may contain from6 to 24, preferably 6 to 18, more preferably 6 to 16, and especially 6to 14, carbon atoms. Preferred aryl groups include phenyl, naphthyl,anthryl, phenanthryl and pyryl groups, especially a phenyl or naphthyl,and particularly a phenyl, group. When an aryl moiety forms part ofanother group, for example the aryl moiety of an aralkyl group, it ispreferred that it is a phenyl, naphthyl, anthryl, phenanthryl or pyryl,especially phenyl or naphthyl, and particularly a phenyl, moiety.

An aralkyl group may be any alkyl group substituted by an aryl group. Apreferred aralkyl group contains from 7 to 30, particularly 7 to 24 andespecially 7 to 18, carbon atoms, particularly preferred aralkyl groupsbeing benzyl, naphthylmethyl, anthrylmethyl, phenanthrylmethyl andpyrylmethyl groups. A particularly preferred aralkyl group is a benzylgroup.

A cycloalkyl group may be any saturated cyclic hydrocarbon group and maycontain from 3 to 12, preferably 3 to 8, and especially 3 to 6, carbonatoms. Preferred cycloalkyl groups are cyclopropyl, cyclopentyl andcyclohexyl groups.

A heteroaryl group may be any aromatic monocyclic or polycyclic ringsystem which contains at least one heteroatom. Preferably, a heteroarylgroup is a 5- 18-membered, particularly a 5- to 14-membered, andespecially a 5- to 10-membered, aromatic ring system containing at leastone heteroatom selected from oxygen, sulphur and nitrogen atoms.Preferred heteroaryl groups include pyridyl, pyrylium, thiopyrylium,pyrrolyl, furyl, thienyl, indolinyl, isoindolinyl, indolizinyl,imidazolyl, pyridonyl, pyronyl, pyrimidinyl, pyrazinyl, oxazolyl,thiazolyl, purinyl, quinolinyl, isoquinolinyl, quinoxalinyl,pyridazinyl, benzofuranyl, benzoxazolyl and acridinyl groups. A C-linkedheteroaryl group is therefore a heteroaryl group as defined above whichis linked to the tetracyclic 1,2,4-trioxane moiety of a compound ofgeneral formula I via a carbon atom in the heteroaromatic ring system.

A heterocyclic group may be any monocyclic or polycyclic ring systemwhich contains at least one heteroatom and may be unsaturated orpartially or fully saturated. The term “heterocyclic” thus includesheteroaryl groups as defined above as well as non-aromatic heterocyclicgroups. Preferably, a heterocyclic group is a 3- to 18-membered,particularly a 3- to 14-membered, especially a 5- to 10-membered, ringsystem containing at least one heteroatom selected from oxygen, sulphurand nitrogen atoms. Preferred heterocyclic groups include the specificheteroaryl groups named above as well as pyranyl, piperidinyl,pyrrolidinyl, dioxanyl, piperazinyl, morpholinyl, thiomorpholinyl,morpholinosulphonyl, tetrahydroisoquinolinyl and tetrahydrofuranylgroups.

A heterocyclylalkyl group may be any alkyl group substituted by aheterocyclic group. Preferably, the heterocyclic moiety is a 3- to18-membered, particularly a 3- to 14-membered, and especially a 5- to10-membered, heterocyclic group as defined above and the alkyl moiety isa C₁₋₆ alkyl, preferably C₁₋₄ alkyl, and especially methyl, group.

An amino acid may be any α-amino acid, such as glycine, alanine, valine,leucine, isoleucine, serine, threonine, cysteine, cystine, methionine,aspartic acid, glutamic acid, aspargine, glutamine, lysine,hydroxylysine, arginine, histidine, phenylalanine, tyrosine, tryptophan,proline, hydroxyproline or phenylglycine, and includes both D- andL-configurations. An amino acid ester may be any ester of such an aminoacid, alkyl esters, particularly C₁₋₄ alkyl esters, being especiallypreferred.

When any of the foregoing substituents are designated as beingoptionally substituted, the substituent groups which are optionallypresent may be any one or more of those customarily employed in thedevelopment of pharmaceutical compounds and/or the modification of suchcompounds to influence their structure/activity, stability,bioavailability or other property. Specific examples of suchsubstituents include, for example, halogen atoms, nitro, cyano,hydroxyl, cycloalkyl, alkyl, alkenyl, haloalkyl, alkoxy, haloalkoxy,amino, alkylamino, dialkylamino, formyl, alkoxycarbonyl, carboxyl,alkanoyl, alkylthio, alkylsulphinyl, alkylsulphonyl, alkylsulphonato,arylsulphinyl, arylsulphonyl, arylsulphonato, carbamoyl, alkylamido,aryl, aralkyl, optionally substituted aryl, heterocyclic and alkyl- oraryl-substituted heterocyclic groups. When any of the foregoingsubstituents represents or contains an alkyl or alkenyl substituentgroup, this may be linear or branched and may contain up to 12,preferably up to 6, and especially up to 4, carbon atoms. A cycloalkylgroup may contain from 3 to 8, preferably from 3 to 6, carbon atoms. Anaryl group or moiety may contain from 6 to 10 carbon atoms, phenylgroups being especially preferred. A heterocyclic group or moiety may bea 5- to 10-membered ring system as defined above. A halogen atom may bea fluorine, chlorine, bromine or iodine atom and any group whichcontains a halo moiety, such as a haloalkyl group, may thus contain anyone or more of these halogen atoms.

In one aspect, it is preferred that Y represents a halogen atom,particularly a fluorine or bromine, and especially a fluorine, atom.

In another preferred aspect Y may represent a C₃₋₈ cycloalkyl group, aC₆₋₁₈ aryl group, a 5- to 10-membered C-linked heteroaryl group or a 5-to 10-membered heterocyclyl-C₁₋₆ alkyl group, each group beingoptionally substituted by one or more substituents selected from thegroup consisting of halogen atoms, hydroxyl, C₁₋₄ alkyl, C₂₋₄ alkenyl,C₁₋₄ haloalkyl, C₁₋₄ alkoxy, amino, C₁₋₄ alkylamino, di(C₁₋₄alkyl)amino, carboxyl, C₆₋₁₀ aryl, 5 to 10-membered heterocyclic andC₁₋₄ alkyl- or phenyl-substituted 5- to 10-membered heterocyclic groups.Preferably Y represents a C₆₋₁₈ aryl group optionally substituted by oneor more substituents selected from the group consisting of halogenatoms, hydroxyl, C₁₋₄ alkyl, C₂₋₄ alkenyl, C₁₋₄ haloalkyl, C₁₋₄ alkoxy,C₁₋₄ haloalkoxy, amino, C₁₋₄ alkylamino, di(C₁₋₄ alkyl)amino andcarboxyl groups. In particular, Y may represent a phenyl, naphthyl,anthryl or phenanthryl group, each group being optionally substituted byone or more substituents selected from the group consisting of halogenatoms and hydroxyl, methyl, vinyl, C₁₋₄ alkoxy and carboxyl groups.

In a particularly preferred sub-group of compounds, Y represents aphenyl, fluorophenyl, chlorophenyl, bromophenyl, trimethylphenyl,vinylphenyl, methoxyphenyl, dimethoxyphenyl, trimethoxyphenyl,carboxylphenyl, naphthyl, hydroxynaphthyl, methoxynaphthyl, anthryl orphenanthryl group. Compounds in which Y represents a phenyl ortrimethoxyphenyl group are especially preferred.

In a further preferred aspect, Y may represent a group —NR¹R² where R¹represents a hydrogen atom or a C₁₋₆ alkyl group and R² represents aC₁₋₆ alkyl, C₃₋₈ cycloalkyl, C₆₋₁₀ aryl or C₇₋₁₆ aralkyl group, or R¹and R² together with the interjacent nitrogen atom represent a 5- to10-membered heterocyclic group or an amino group derived from a C₁₋₆alkyl ester of an amino acid, each group being optionally substituted byone or more substituents selected from the group consisting of halogenatoms, C₁₋₄ alkyl, C₁₋₄ haloalkyl, C₁₋₆ alkoxycarbonyl, phenyl,halophenyl, C₁₋₄ alkylphenyl, C₁₋₄ haloalkylphenyl, C₁₋₄ alkoxyphenyl,benzyl, pyridyl and pyrimidinyl groups. In particular, Y may represent agroup —NR¹R² where R¹ represents a hydrogen atom or a C₁₋₄ alkyl groupand R² represents a C₁₋₄ alkyl, C₃₋₆ cycloalkyl, phenyl or benzyl group,or R¹ and R² together with the interjacent nitrogen atom represent a 6-to 10-membered heterocyclic group or an amino group derived from a C₁₋₄alkyl ester of an amino acid, each group being optionally substituted byone or more substituents selected from the group consisting of halogenatoms, C₁₋₄ haloalkyl, C₁₋₄ alkoxycarbonyl, phenyl, halophenyl, C₁₋₄alkylphenyl, C₁₋₄ haloalkylphenyl, C₁₋₄ alkoxyphenyl, benzyl, pyridyland pyrimidinyl groups.

In a particularly preferred sub-group of these compounds, Y represents apropylamino, cyclopentylamino, cyclohexylamino, phenylamino,fluorophenylamino, chlorophenylamino, bromophenylamino, iodophenylamino,methoxycarbonylphenylamino, biphenylamino, benzylamino,fluorobenzylamino, bis(trifluoromethyl)-benzylamino, phenylethylamino,phenylmethoxycarbonylmethylamino, diethylamino, morpholinyl,thiomorpholinyl, morpholinosulphonyl, indolinyl,tetrahydroisoquinolinyl, phenylpiperazinyl, fluorophenylpiperazinyl,chlorophenylpiperazinyl, methylphenylpiperazinyl,trifluoromethylphenylpiperazinyl, methoxyphenylpiperazinyl,benzylpiperazinyl, pyridylpiperazinyl and pyrimidinylpiperazinyl group.Compounds in which Y represents a propylamino, phenylamino,bromophenylamino, iodophenylamino, biphenylamino, benzylamino,bis(trifluoromethyl)benzylamino, phenylethylamino,phenyl-methoxycarbonylmethylamino or morpholinyl group are especiallypreferred.

Preferably, the parasite is an organism of the genus Neospora or thegenus Eimeria.

The present invention also provides the use of a compound of the generalformula I as defined above for the manufacture of a medicament for thetreatment and/or prophylaxis of a disease caused by infection with aparasite other than an organism of the genus Plasmodium. Preferably, theparasite is an organism of the genus Neospora or the genus Eimeria.

Certain compounds of the general formula I are novel and the inventiontherefore further provides a compound of the general formula I asdefined above, with the proviso that, when Y is a group —NR¹R² and R²represents a phenyl, 3-chlorophenyl, 4-chlorophenyl, 3-bromophenyl,4-bromophenyl, 4-iodophenyl, 4-methylphenyl, 4-methoxyphenyl,3-carboxylphenyl or 4-carboxylphenyl group, then R¹ is an optionallysubstituted alkyl group.

It should also be appreciated that the compounds of general formula Iare capable of existing as different geometric and optical isomers. Thepresent invention thus includes both the individual isomers and mixturesof such isomers.

The present invention also provides a process for the preparation of anovel compound of the general formula I as defined in the ante-precedingparagraph which comprises reacting a compound of the general formula II

in which Q represents a hydrogen atom or trimethylsilyl group, with asuitable halogenating agent to form a compound of the general formula Iin which Y represents a halogen atom; and, if desired, reacting thecompound of general formula I thus formed either with a Grignard reagentof the general formula YMgX where Y is an optionally substitutedcycloalkyl, aryl, C-linked heteroaryl or heterocyclylalkyl group and Xis a halogen atom to form a compound of general formula I in which Yrepresents an optionally substituted cycloalkyl, aryl, C-linkedheteroaryl or heterocyclylalkyl group or with an amine of the generalformula HNR¹R² where R¹ and R² are as defined above to form a compoundof general formula I in which Y represents a group —NR¹R² where R¹ andR² are as defined above.

Suitable halogenating agents for forming compounds of the generalformula I in which Y represents a halogen atom includediethylaminosulphur trifluoride, chlorotrimethylsilane,bromotrimethylsilane and iodotrimethylsilane. In particular, compoundsof the general formula I in which Y represents a chlorine, bromine oriodine atom may be prepared by reacting a compound of the generalformula II in which Q represents a trimethylsilyl group with a suitablechlorinating, brominating or iodinating agent respectively, such aschlorotrimethlysilane, bromotrimethylsilane or iodotrimethylsilanerespectively. This reaction may be conveniently carried out in thepresence of a solvent. Suitable solvents include halogenatedhydrocarbons, especially chlorinated hydrocarbons, such asdichloromethane. Preferably, the reaction is carried out at atemperature of −30° C. to +10°, particularly −5° C. to +5° C., about 0°C. being especially preferred.

Compounds of the general formula I in which Y represents a fluorine atommay be conveniently prepared by reacting a compound of the generalformula II in which Q represents a hydrogen atom with a suitablefluorinating agent, such as diethylaminosulphur trifluoride. Thisreaction may be conveniently carried out in the presence of a solvent,suitable solvents including halogenated hydrocarbons, especiallychlorinated hydrocarbons, such as dichloromethane. Preferably, thereaction is carried out at −5° C. to room temperature, that is, −5 to+35° C., preferably 0 to 30° C. The reaction may also be carried outunder an inert atmosphere, such as nitrogen.

Suitable Grignard reagents for forming compounds of the general formulaI in which Y is an optionally substituted cycloalkyl, aryl, C-linkedheteroaryl or heterocyclylalkyl group include compounds of the generalformula YMgX where X represents a chlorine, bromine or iodine atom.However, it is particularly preferred that X represents a bromine atom.The reaction of a compound of the general formula I in which Yrepresents a halogen, preferably a bromine, atom with a Grignard reagentmay be conveniently carried out in the presence of a solvent. Suitablesolvents include ethers, such as diethyl ether. Preferably, the reactionis carried out under an inert atmosphere, such as nitrogen, at atemperature of −5° C. to +5° C., 0° C. being especially preferred. Thismethod produces a single pure isomer of the final product.

The reaction of an amine with a compound of the general formula I inwhich Y represents a halogen, preferably a bromine, atom to form acompound of the general formula I in which Y represents a group —NR¹R²where R¹ and R² are as defined above may be conveniently carried out inthe presence of a solvent. Suitable solvents include halogenatedhydrocarbons, especially chlorinated hydrocarbons, such asdichloromethane, and ethers, such as tetrahydrofuran. Preferably, thereaction is carried out at a temperature of −5° C. to +5° C., 0° C.being especially preferred.

When a compound of the general formula I in which Y represents a bromineatom is to be further reacted with a Grignard reagent or an amine toform a compound of the general formula I in which Y represents anoptionally substituted cycloalkyl, aryl, C-linked heteroaryl orheterocyclylalkyl group or a group —NR¹R² where R¹ and R² are as definedabove, it is preferred that the compound of the general formula I inwhich Y represents a bromine atom is generated in situ by reacting acompound of the general formula II in which Q represents atrimethylsilyl group with bromotrimethylsilane.

A compound of the general formula II in which Q represents atrimethylsilyl group may be prepared by reacting dihydroartemisinin,that is, the compound of general formula II in which Q represents ahydrogen atom, with chlorotrimethylsilane in the presence of a base,such as pyridine or triethylamine. Preferably, the reaction is carriedout at room temperature, that is, 15 to 35° C., preferably 20 to 30° C.

Dihydroartemisinin, that is, the compound of general formula II in whichQ represents a hydrogen atom, is a known compound and can be prepared byknown processes.

Compounds of the general formula I in which Y represents an optionallysubstituted cycloalkyl, aryl, C-linked heteroaryl or heterocyclylalkylgroup can also be prepared by reacting 9,10-anhydroartemisinin with acompound of the general formula Y—H, where Y is as defined above, in thepresence of a suitable Lewis acid. This method produces a mixture ofisomers in the final product.

Suitable Lewis acids include boron trifluoride dietherate andtrifluoromethanesulphonic acid. The reaction may be conveniently carriedout in the presence of a solvent. Suitable solvents include halogenatedhydrocarbons, especially chlorinated hydrocarbons, such asdichloromethane. Preferably, the reaction is carried out under an inertatmosphere, such as nitrogen, at room temperature, that is, 15 to 35°C., preferably 20 to 30° C.

9,10-Anhydroartemisinin may be conveniently prepared by reactingdihydroartemisinin with trifluoroacetic anhydride. The reaction may beconveniently carried out in the presence of a solvent, preferably ahalogenated hydrocarbon, and especially a chlorinated hydrocarbon, suchas dichloromethane. It is also preferred that the reaction is carriedout in the presence of a base, such as pyridine or a derivative thereof,for example, dimethylamino-pyridine. Preferably, the reaction is carriedout under an inert atmosphere, such as nitrogen, at a temperature of −5°C. to +5° C., preferably 0° C., with the reaction mixture beingsubsequently allowed to warm to room temperature, that is, 15 to 35° C.,preferably 20 to 30° C.

Compounds of the general formula I in which Y represents an optionallysubstituted aryl or C-linked heteroaryl group can also be prepared byreacting 10-trichloroacetimidoyl-10-deoxoartemisinin with a compound ofthe general formula Y—H, where Y is as defined above, in the presence ofa suitable Lewis acid, such as boron trifluoride diethyl etherate. It ispreferred that the 10-trichloroacetimidoyl-10-deoxoartemisinin isgenerated in situ by reacting a compound of the general formula II inwhich Q represents a hydrogen atom with trichloroacetonitrile in thepresence of a suitable base, such as 1,8-diazabicyclo[5.4.0]undecane.Preferably, the reaction to form10-trichloroacetimidoyl-10-deoxoartemisinin is carried out at roomtemperature, that is, 15 to 35° C., preferably 20 to 30° C. The reactionmay be conveniently carried out in the presence of a solvent. Suitablesolvents include halogenated hydrocarbons, especially chlorinatedhydrocarbons, such as dichloromethane. Preferably, the remainder of thereaction is carried out under an inert atmosphere, such as nitrogen.Preferably, the remainder of the reaction is carried out at atemperature of −60 to −20° C., particularly −55 to −30° C., andespecially −40 to −50° C.

Compounds of the general formula I in which Y represents an optionallysubstituted aryl or C-linked heteroaryl group can also be prepared byreacting a 10-acyloxyartemisinin compound in which the acyloxy group isof formula A(C═O)—O—, where A represents an optionally substitutedalkyl, cycloalkyl, aryl, aralkyl, heterocyclic or polycyclic group, witha compound of the general formula Y—H, where Y is as defined above, inthe presence of a suitable Lewis acid. Suitable Lewis acids includeboron trifluoride diethyl etherate, tin(IV) chloride,copper(II)-trifluoromethanesulfonate and trifluoromethanesulphonic acid.It is preferred that the Lewis acid is boron trifluoride diethyletherate.

When A represents an optionally substituted alkyl group, unlessotherwise specified, this may be linear or branched and may contain upto 12, preferably up to 6, and especially up to 4 carbon atoms.Preferred alkyl groups are methyl, ethyl, propyl and butyl.

When A represents an optionally substituted aryl group, this may be anyaromatic hydrocarbon group and may contain from 6 to 24, preferably 6 to18, more preferably 6 to 16, and especially 6 to 14, carbon atoms.Preferred aryl groups include phenyl, naphthyl, anthryl, phenanthryl andpyryl groups, especially phenyl, naphthyl and anthryl groups. When anaryl moiety forms part of another group, for example the aryl moiety ofan aralkyl group, it is preferred that it is a phenyl, naphthyl,anthryl, phenanthryl or pyryl, especially a phenyl or naphthyl, andparticularly a phenyl, moiety.

When A represents an optionally substituted aralkyl group, this may beany alkyl group substituted by an aryl group. A preferred aralkyl groupcontains from 7 to 30, particularly 7 to 24, more particularly 7 to 18,and especially 7 to 10, carbon atoms, particularly preferred aralkylgroups being benzyl, naphthylmethyl, anthrylmethyl, phenanthrylmethyland pyrylmethyl groups, a benzyl group being especially preferred.

When A represents an optionally substituted cycloalkyl group, this maybe any saturated or partially unsaturated cyclic hydrocarbon group andmay contain from 3 to 12, preferably 3 to 8, and especially 3 to 6,carbon atoms. Preferred cycloalkyl groups are cyclopropyl, cyclopentyland cyclohexyl groups.

When A represents an optionally substituted polycyclic group, this maybe any saturated or partially unsaturated hydrocarbon group whichcontains more than one ring system. Such ring systems may be “fused”,that is, adjacent rings have two adjacent carbon atoms in common,“bridged”, that is, the rings are defined by at least two common carbonatoms (bridgeheads) and at least three acyclic chains (bridges)connecting the common carbon atoms, or “spiro” compounds, that is,adjacent rings are linked by a single common carbon atom. It is alsoenvisaged that a polycyclic group may contain more than one of thesetypes of ring system. Polycyclic groups preferably contain from 4 to 30,particularly 4 to 26, and especially 6 to 18, carbon atoms. Bicyclic,tricyclic and tetracyclic groups are particularly preferred. Preferredbicyclic groups contain from 4 to 14, especially 6 to 10, carbon atoms.Preferred tricyclic groups contain from 5 to 20, especially 6 to 14,carbon atoms with anthraquinone groups being especially preferred.Preferred tetracyclic groups contain from 6 to 26, especially 6 to 18,carbon atoms.

Optional substituents for the substituent A may be any of thosepreviously identified as suitable in this respect.

The reaction may be conveniently carried out in the presence of asolvent. Suitable solvents include halogenated hydrocarbons, especiallychlorinated hydrocarbons, such as dichloromethane. Preferably, thereaction is carried out under an inert atmosphere, such as nitrogen.Preferably, the reaction is carried out at a temperature of −60 to −20°C., particularly −55 to −30° C., and especially −40 to −50° C.

Compounds of formula I in which Y represents a substituted aryl groupwhere at least one of the substituents is a hydroxyl group can also beprepared by rearrangement of the corresponding C-10 ether linkedartemisinin derivative so that the oxygen atom of the ether link becomesthe oxygen atom of the hydroxyl group in the substituted aryl group ofthe desired product. Such a rearrangement can be effected by reactingthe corresponding C-10 ether linked artemisinin derivative with a Lewisacid, such as a boron trifluoride dietherate. The reaction isconveniently carried out in the presence of a solvent such asdichloromethane at a temperature of −5° C. to +50° C., preferably 0° C.

Certain compounds of the general formula I may also be prepared byconversion of another compound of general formula I For instance,10-(4-vinylphenyl)-dihydroartemisinin may be converted to10-(4-carboxyphenyl)dihydroartemisinin by reaction with an oxidisingagent, such as potassium permanganate. Also, compounds of generalformula I which contain a heterocyclic moiety having at least onesulphur atom in the ring system may be oxidised to form compounds ofgeneral formula I in which the or each sulphur atom has been convertedto a sulphinyl or sulphonyl group by reaction with a suitable oxidisingagent. Suitable oxidising agents include 4-methylmorpholine N-oxide(NMO), tetrapropylammonium perruthenate (TPAP) and mixtures thereof. Thereaction may be conveniently carried out in the presence of a solvent,suitable solvents including halogenated hydrocarbons, especiallychlorinated hydrocarbons, such as dichloromethane. Preferably, thereaction is carried out at room temperature, that is, 15 to 35° C.,preferably 20 to 30° C. The reaction may also be carried out under aninert atmosphere, such as nitrogen.

The invention also provides a pharmaceutical composition which comprisesa carrier and, as active ingredient, a novel compound of the generalformula I as defined above.

A pharmaceutically acceptable carrier may be any material with which theactive ingredient is formulated to facilitate administration. A carriermay be a solid or a liquid, including a material which is normallygaseous but which has been compressed to form a liquid, and any of thecarriers normally used in formulating pharmaceutical compositions may beused. Preferably, compositions according to the invention contain 0.5 to95% by weight of active ingredient.

The compounds of general formula I can be formulated as, for example,tablets, capsules, suppositories or solutions. These formulations can beproduced by known methods using conventional solid carriers such as, forexample, lactose, starch or talcum or liquid carriers such as, forexample, water, fatty oils or liquid paraffins. Other carriers which maybe used include materials derived from animal or vegetable proteins,such as the gelatins, dextrins and soy, wheat and psyllium seedproteins; gums such as acacia, guar, agar, and xanthan; polysaccharides;alginates; carboxymethylcelluloses; carrageenans; dextrans; pectins;synthetic polymers such as polyvinylpyrrolidone; polypeptide/protein orpolysaccharide complexes such as gelatin-acacia complexes; sugars suchas mannitol, dextrose, galactose and trehalose; cyclic sugars such ascyclodextrin; inorganic salts such as sodium phosphate, sodium chlorideand aluminium silicates; and amino acids having from 2 to 12 carbonatoms such as a glycine, L-alanine, L-aspartic acid, L-glutamic acid,L-hydroxyproline, L-isoleucine, L-leucine and L-phenylalanine.

Auxiliary components such as tablet disintegrants, solubilisers,preservatives, antioxidants, surfactants, viscosity enhancers, colouringagents, flavouring agents, pH modifiers, sweeteners or taste-maskingagents may also be incorporated into the composition. Suitable colouringagents include red, black and yellow iron oxides and FD & C dyes such asFD & C blue No. 2 and FD & C red No. 40 available from Ellis & Everard.Suitable flavouring agents include mint, raspberry, liquorice, orange,lemon, grapefruit, caramel, vanilla, cherry and grape flavours andcombinations of these. Suitable pH modifiers include citric acid,tartaric acid, phosphoric acid, hydrochloric acid and maleic acid.Suitable sweeteners include aspartame, acesulfame K and thaumatin.Suitable taste-masking agents include sodium bicarbonate, ion-exchangeresins, cyclodextrin inclusion compounds, adsorbates ormicroencapsulated actives.

For treatment of and prophylaxis against coccidiosis and relatedparasites, for instance, in poultry, especially in chickens, ducks,geese and turkeys, 0.1 to 100 ppm, preferably 0.5 to 100 ppm of theactive compound may be mixed into an appropriate, edible material, suchas nutritious food. If desired, the amounts applied can be increased,especially if the active compound is well tolerated by the recipient.Accordingly, the active compound can be applied with the drinking water.

For the treatment of a single animal, for instance, for the treatment ofcoccidiosis in mammals or toxoplasmosis, amounts of 0.5 to 100 mg/kgbody weight active compound are preferably administered daily to obtainthe desired results. Nevertheless, it may be necessary from time to timeto depart from the amounts mentioned above, depending on the body weightof the experimental animal, the method of application, the animalspecies and its individual reaction to the drug or the kind offormulation or the time or interval in which the drug is applied. Inspecial cases, it may be sufficient to use less than the minimum amountgiven above, whilst in other cases the maximum dose may have to beexceeded. For a larger dose, it may be advisable to divide the dose intoseveral smaller single doses.

The invention also includes a novel compound of the general formula I asdefined above for use in the treatment and/or prophylaxis of a diseasecaused by infection with a parasite of the genus Plasmodium and use of anovel compound of the general formula I as defined above for themanufacture of a medicament for the treatment and/or prophylaxis of adisease caused by infection with a parasite of the genus Plasmodium.Preferred compounds in this respect include compounds of the generalformula I in which Y represents a fluorine atom, Y represents a phenyl,dimethoxyphenyl or trimethoxyphenyl group or Y represents a propylamino,fluorophenylamino, biphenylamino, benzylamino, phenylethylamino,phenylmethoxycarbonylmethylamino or diethylamino group.

The invention also provides a method for treating a disease caused byinfection with a parasite other than an organism of the genus Plasmodiumwhich comprises administering to a host in need of such treatment atherapeutically effective amount of a compound of the general formula Ias first defined above. Preferably, the parasite is an organism of thegenus Neospora or the genus Eimeria. A method for treating a diseasecaused by infection with a parasite of the genus Plasmodium is alsoprovided which comprises administering to a host in need of suchtreatment a therapeutically effective amount of a novel compound of thegeneral formula I as defined above.

The invention is further illustrated by the following examples.

EXAMPLE 1 Preparation of 10β-fluoro-10-deoxo-10-dihydro-artemisinin(10β-fluoro-10-deoxodihydroartemisinin) (Formula I: Y=F)

A solution of dihydroartemisinin (1.136 g, 4 mmol) in dichloromethane(24 ml) was cooled to 0° C. under nitrogen and diethylaminosulphurtrifluoride (DAST) (0.6 ml, 4.8 mmol) was added. The reaction mixturewas allowed to warm up to room temperature and then stirred undernitrogen for 24 hours. The yellow solution was cooled again to 0° C.,Na₂CO₃ solution (5%, 20 ml) was added and the mixture was stirred for 2hours at room temperature. After this the two phases were separated andthe organic layer was washed with 1 molar HCl, 5% NaHCO₃ and water anddried over MgSO₄. Immediately after evaporating the solvent, the residuewas purified twice by flash colum chromatography (10% ethylacetate/hexane), followed by recrystallisation from hexane (289 mg,50.5%); ¹H NMR(300 MHz, CDCl₃): δ ppm 0.97 (d, J_(6-Me,6)=6.1 Hz, 3 H,6-CH₃), 1.00 (d, J_(9-Me,9)=7.4 Hz, 3 H, 9-CH₃), 1.13-1.47 (m, 3 H),1.44 (s, 3 H, 3-CH₃), 1.47-1.72 (m, 4 H), 1.82-1.96 (m, 2 H), 2.05 (ddd,J=14.6 Hz, J=4.9 Hz, J=3.0 Hz, 1 H), 2.39 (td, J=13.5 Hz, J=4.0 Hz, 1H), 2.64 (dm, J_(9,F)=36.1 Hz, 1 H, H-9), 5.60 (dd, J_(10-F)=54.4 Hz,J_(10,9)=2.4 Hz, 1 H, H-10), 5.56 (d, J=1.83 Hz, 1 H, H-12); ¹⁹F NMR(282MHz, CDCl₃): δ (ppm)=−136.43 (dd, J_(F,10)=54.1 Hz, J_(F,9)=36.0 Hz); MS(CI,NH₃): m/z (%)=304 [M⁺+NH₄ ⁺] (18), 286 [M⁺], 284 [304-HF] (100), 267(64), 256 (28), 239 (16), 221 (12), 163 (8), 52 (28).

EXAMPLE 2 Preparation of 10β-phenyl-10-deoxo-10-dihydroartemisinin(10β-(phenyl)dihydroartemisinin) (Formula I: Y=phenyl)

(a) Preparation of 10-(trimethylsiloxy)dihydro-artemisinin (Formula II:Q=—Si(CH₃₎ ₃)

Method 1

To a solution of dihydroartemisinin (1.51 g, 5.32 mmol) in pyridine (20ml) at 0° C. under nitrogen was added dropwise chlorotrimethylsilane(5.20 ml, mmol). The mixture was stirred at room temperature for afurther 1 hour and poured into ice-water mixture. The solution wasextracted with diethyl ether (3×15 ml), dried (MgSO₄) and concentratedin vacuo. The residue was purified by flash chromatography (SiO₂; 5%ethyl acetate/hexanes) to give 10-(trimethylsiloxy)dihydro-artemisininas a white solid (1.47 g, 78%). δ_(H) 5.49 (1H, s, H-12), 5.19 (1H, d,J=3.05 Hz, H-10), 2.52-2.62 (1H, m, H-9), 2.39 (1H, ddd, J=17.5, 13.4,4.01 Hz), 2.04 (1H, ddd, J=14.5, 4.84, 3.05 Hz), 1.20-1.97 (9H, m), 1.45(3H, s, H-14), 0.97 (3H, d, J=6.24 Hz; H-16), 0.87 (3H, d, J=7.29 Hz,H-15), 0.17 (9H, s, (CH ₃)₃Si).

Method 2

Preparation of 10α-(trimethylsiloxy)dihydro-artemisinin (Formula II:Q=—Si(CH₃)₃)

To a solution of dihydroartemisinin (1.51 g, 5.32 mmol) indichloromethane (40 ml) at 0° C. under nitrogen was added dropwisetriethylamine (0.94 ml, 6.65 mmol) and chlorotrimethylsilane (0.84 ml,6.65 mmol). The mixture was stirred at room temperature for a further 1hour and poured into ice-water mixture. The aqueous solution wasextracted with dichloromethane (2×20 ml). The combined organic layerswere dried (MgSO₄) and concentrated in vacuo. The residue was purifiedby flash chromatography (SiO₂; 5% ethyl acetate/hexanes) to give10α-(trimethylsiloxy)dihydro-artemisinin as a white solid (1.48 g, 78%).δ_(H) 5.32 (1H, s, H-12), 4.76 (1H, d, J=9.00 Hz, H-10), 2.25-2.45 (2H,m, H-8, H-9), 2.01 (1H, m, H-4), 1.89 (1H, m, H-5), 1.18-1.79 (8H, m,H-2a, H-2b, H-3a, H-3b, H-6a, H-6b, H-7a, H-7b), 1.31 (3H, s, 1-CH₃)0.95 (3H, d, J=5.88 Hz, 9-CH₃), 0.86 (3H, d, J=7.14 Hz, 5-CH₃), 0.20(9H, s, Me₃Si) ppm.

(b) Preparation of 10-bromo-10-deoxo-10-dihydroartemisinin(10-bromoartemisinin) (Formula I: Y=Br)

A solution of 10α-(trimethylsiloxy)dihydroartemisinin (372 mg, 1.04mmol) prepared as described in (a) Method 2 above in dichloromethane (5ml) at 0° C. was treated dropwise with bromotrimethylsilane (140 μl,1.06 mmol). The mixture was stirred at 0° C. for a further 30 minutes toproduce 10-bromoartemisinin in situ.

(c) Preparation of 10β-phenyl-10-deoxo-10-dihydro-artemisinin(10β-(phenyl)dihydroartemisinin) (Formula I: Y=phenyl).

The solution prepared in (b) above was concentrated in vacuo. Theresidue was dissolved in diethyl ether (5 ml). To this solution wasadded phenylmagnesium bromide (1.40 ml, 2.38 mmol, 1.7M) at 0° C. undernitrogen. The mixture was then stirred at 0° C. and then allowed toreach room temperature overnight. The solution was then quenched withsaturated ammonium chloride solution, dried (MgSO₄) and concentrated invacuo. The residue was purified by flash chromatography (SiO₂; 8% ethylacetate/hexanes to give 10β-phenyl-10-deoxo-10-dihydroartemisinin(10β-(phenyl)dihydroartemisinin) (159 mg, 45%) as a white solid.Recrystallisation from ether/hexane mixture gave a colourlessrectangular crystal. M.p. 122° C.; [α]_(D) ²⁰ −36.0° (c 0.47/CHCl₃);νmax (film) 2938, 2874, 1494, 1452, 1376, 1208, 1112, 1076, 1058, 1038,1010, 954, 944, 904, 882, 852, 820, 740, 700; δ_(H) 7.19-7.34 (5H, m,Ar—H), 5.75 (1H, d, J=6.70 Hz, H-10), 5.60 (1H, s, H-12), 2.71-2.84 (1H,m, H-9), 2.31-2.42 (1H, m), 1.65-2.12 (5H, m), 1.28-1.60 (5H, m), 1.41(3H, s, H-14), 1.01 (1H, d, J=5.77 Hz, H-16), 0.54 (1H, d, J=7.68 Hz,H-15); δ_(C) 141.03, 127.67, 126.24, 126.09, 102.22, 90.82, 81.10,72.99, 51.46, 43.45, 37.46, 36.64, 34.16, 32.08, 25.68, 24.88, 24.71,19.85, 13.62; m/z (CI, CH₄) 345 (M⁺+1, 14%), 327 (14), 299 (100); Anal.Calc. for C₂₁H₂₈O₄: C, 73.26; H, 8.14. Found: C, 73.58; H, 8.32.nOe-difference experiment: irradiation of the doublet signal of H-10 atδ 5.75 gave 10% enhancement in the multiplet signal of H-9 at δ 2.75;this showed that the stereochemistry of H-10 and H-9 are syn to eachother.

EXAMPLE 3 Preparation of10α-(4′-fluorobenzylamino)-10-deoxo-10-dihydroartemisinin(10α-(4′-fluorobenzylamino)dihydro-artemisinin) (Formula I: Y=—NR¹R²;R¹=H; R²=4-F benzyl)

(a) Preparation of 10α-(trimethylsiloxy)dihydro-artemisinin (Formula II:Q=—Si(CH₃)₃)

To a solution of dihydroartemisinin (1.51 g, 5.32 mmol) indichloromethane (40 ml) at 0° C. under nitrogen was added dropwisetriethylamine (0.94 ml, 6.65 mmol) and chlorotrimethylsilane (0.84 ml,6.65 mmol). The mixture was stirred at room temperature for a further 1hour and poured into ice-water mixture. The aqueous solution wasextracted with dichloromethane (2×20 ml). The combined organic layerswere dried (MgSO₄) and concentrated in vacuo. The residue was purifiedby flash chromatography (SiO₂; 5% ethyl acetate/hexanes) to give10α-(trimethylsiloxy)dihydroartemisinin as a white solid (1.48 g, 78%).δ_(H) 5.32 (1H, s, H-12), 4.76 (1H, d, J 9.00 Hz, H-10), 2.25-2.45 (2H,m, H-8, H-9), 2.01 (1H, m, H-4), 1.89 (1H, m, H-5), 1.18-1.79 (8H, m,H-2a, H-2b, H-3a, H-3b, H-6a, H-6b, H-7a, H-7b), 1.31 (3H, s, 1-CH₃)0.95 (3H, d, J 5.88 Hz, 9-CH₃), 0.86 (3H, d, J 7.14 Hz, 5-CH₃), 0.20(9H, s, Me₃Si) ppm.

(b) Preparation of10α-(4′-fluorobenzylamino)-10-deoxo-10-dihydroartemisinin(10α-(4′-fluorobenzylamino)dihydroartemisinin) (Formula I: Y=—NR¹R²;R¹=H; R²=4-F-benzyl)

A solution of 10α-(trimethylsiloxy)dihydroartemisinin (214 mg, 0.600mmol) prepared as described in (a) above in dichloromethane (5 ml) at 0°C. was treated dropwise with bromotrimethylsilane (80 μl, 0.600 mmol).The mixture was stirred at 0° C. for a further 30 minutes after which itwas then transferred by cannula into a solution of 4-fluorobenzylamine(140 μl 1.20 mmol) in tetrahydrofuran (5 ml) at 0° C. The mixture wasstirred at 0° C. and then allowed to reach room temperature overnight.The suspension was washed with saturated NaHCO₃ solution, dried (MgSO₄)and concentrated in vacuo. The residue was purified by flashchromatography (SiO₂; 15% ethyl acetate/hexanes) to give10α-(4′-fluorobenzylamino)-10-deoxo-10-dihydroartemisinin(10α-(4′-fluorobenzylamino)-dihydroartemisinin) (76.9 mg, 33%) and9,10-anhydro-10-deoxoartemisinin (9,10-anhydro-dehydroartemisinin) (84.7mg, 53%), both as white solids. M.p. 45.2-46.3° C.; [α]_(D) ²⁰ −18.2° (c0.055 CHCl₃); δ_(H) 7.32-7.37 (2H, m, Ar—H), 6.95-7.02 (2H, m, Ar—H),5.29 (1H, s, H-12), 4.10 (1H, d, J=13.8 Hz, H-1′), 4.08 (1H, d, J=9.76Hz, H-10), 3.91 (1H, d, J=13.8 Hz, H-1′), 2.33-2.42 (2H, m), 1.85-2.07(3H, m), 1.65-1.77 (2H, m), 1.03-1.75 (5H, m), 1.46 (3H, s, H-14), 0.96(3H, d, J=6.02 Hz, H-16), 0.93 (3H, d, J=7.19 Hz, H15); δ_(C) 136.42 (d,J=3.10 Hz), 129.30 (d, J=7.97 Hz), 114.75 (d, J=21.1 Hz), 103.90, 91.35,85.47, 80.60, 51.66, 47.50, 45.82, 37.23, 36.26, 34.03, 32.72, 26.03,24.61, 21.70, 20.15, 14.06; δ_(F) −118; m/z (CI, CH₄) 392 (M⁺+1, 90%),374 (54), 346 (100), 328 (20), 267 (16), 209 (16), 165 (26), 109 (18).Anal. Calc. for C₂₂H₃₀NO₄F: C, 67.50; H, 7.72; N, 3.58. Found: C, 67.51;H, 7.77; N, 3.49.

EXAMPLE 4 Preparation of10-(2′,4′-dimethoxyphenyl)-10-deoxo-10-dihydroartemisinin(10-(2′,4′-dimethoxyphenyl)dihydro-artemisinin (Formula I:Y=2,4-dimethoxyphenyl)

(a) Preparation of 9,10-anhydro-10-deoxoartemisinin(9,10-anhydroartemisinin)

To a solution of dihydroartemisinin (500 mg, 1.86 mmol) indichloromethane (28 ml) at 0° C. under nitrogen was added4-(N,N-dimethylamino)pyridine (37 mg) and trifluoroacetic anhydride(0.79 ml, 5.58 mmol). The mixture was allowed to warm to roomtemperature and stirred overnight. The solution was then concentrated invacuo. The residue was purified by flash chromatography (SiO₂;ether:hexane from 0.5:9.5 to 1.5:8.5) to give9,10-anhydro-10-deoxoartemisinin (9,10-anhydroartemisinin) (180 mg, 25%)as a white solid. M.p. 100° C.; [α]_(D) ^(20.5) +155.74° (c. 0.0101 inCHCl₃); νmax (film): 2948, 2922, 2862, 2850, 1684, 1432, 1372, 1334,1198, 1178, 1158, 1142, 1114, 1078; 1028, 1016, 992, 954, 944, 904, 880,828, 812; δ_(H): 6.18 (1H, s, H-10), 5.54 (1H, s, H-12), 2.40 (1H, ddd,J=17.1, 13.2, 4.14 Hz, H-9), 2.00-2.09 (2H, m), 1.88-1.95 (1H, m),1.07-1.73 (8H, m), 1.58 (3H, d, J=1.37 Hz, H-16) 1.42 (3H, s, H-14),0.98 (3H, d, J=5.98 Hz, H-15); m/z (EI): 380 (M⁺); Anal. Calc. forC₁₅H₂₂O₄: C, 67.67; H, 8.27. Found: C, 67.63; H, 8.51.

(b) Preparation of10-(2′,4′-dimethoxyphenyl)-10-deoxo-10-dihydroartemisinin(10-(2′,4′-dimethoxy-phenyl)-dihydroartemisinin) (Formula I:Y=2.4-dimethoxyphenyl)

To a solution of 9,10-anhydro-10-deoxoartemisinin(9,10-anhydroartemisinin) (191 mg, 0.71 mmol) prepared as described in(a) above and 1,3-dimethoxybenzene (130 μl, 1.00 mmol) indichloromethane (10 ml) at room temperature under nitrogen was addedboron trifluoride diethyl etherate (2 drops). The solution was stirredfor a further 1 hour, and then quenched with 20% hydrochloric acidsolution (5 ml). The mixture was extracted with diethyl ether (3×20 ml),and the ether extracts were dried (MgSO₄) and concentrated in vacuo. Theresidue was purified by flash chromatography (SiO₂; 15% ethylacetate/hexanes) to give10-(2′,4′-dimethoxyphenyl)-10-deoxo-10-dihydroartemisinin(10-(2′,4′-dimethoxyphenyl)dihydroartemisinin) (89.5, 44%) as a whitesolid. δ_(H) 7.56 (1H, brd, J=8.4 Hz, Ar—H), 6.40-6.58 (2H, m, Ar—H),5.43 (1H, s, H12), 5.42 (1H, s, H-12′), 5.16 (1H, d, J=10.8 Hz, H-10),4.96 (1H, d, J=10.3 Hz, H-10′), 3.82, 3.78 (OMe), 2.37-2.48 (2H, m),1.05-2.07 (10H, m), 1.63 (3H, s, H-14), 1.34 (3H, s, H-14′), 1.00 (3H,d, J=6.22 Hz, H-16′), 0.90-0.93 (3H, m, H-15 & H-16), 0.59 (3H, d,J=7.22 Hz, H-15′); m/z (CI, NH₃) 422 (M+NH₄ ⁻, 26%), 406 (84), 405(M⁺+1, 54), 389 (80), 359 (100), 330 (30), 317 (40), 300 (14). Anal.Calc. for C₂₃H₃₂O₆: C, 68.29; H, 7.97%. Found: C, 68.34; H, 8.09.

EXAMPLE 5 Preparation of 10α-(2′-hydroxy-1′-naphthyl)dihydro artemisinin(Formula I: Y=2-OH naphthyl)

(a) Preparation of 10β-(2′naphthoxy)-dihydroartemisinin

To a solution of dihydroartemisinin (568 mg, 2.00 mmol) and 2-naphthol(288 mg, 2.00 mmol) in tetrahydrofuran (10 ml) was addedtriphenylphosphine (524 mg, 4.00 mmol) and diethyl azodicarboxylate (330μl, 2.00 mmol) at ° C. under nitrogen. The mixture was stirred at roomtemperature overnight. The yellow solution was then concentrated invacuo and the residue purified by flash chromotography (SiO₂; 5% ethylacetate/hexanes) to give 10β-(2′-naphthyloxy)dihydroartemisinin (185 mg,23%) as a white solid.

(b) Preparation of 10α-(2′-hydroxy-1′-naphthyl)-dihydroartemisinin

To a solution of 10β-(2′-naphthoxy)dihydroartemisinin (232 mg, 0.564mmol) prepared as described in (a) above in dichloromethane (10 ml) wasadded boron trifluoride dietherate (220 βl) at 0° C. The mixture wasallowed to warm to room temperature and stirred for a further 30minutes. The solution was washed with 10% sodium hydrogen carbonatesolution (2×5 ml), dried (MgSO₄) and concentrated in vacuo. The residuewas then purified by flash chromatography (SiO₂; 10% ethylacetate/hexanes) to give 10α-(2′-hydroxy-1′-naphthyl)-dihydroartemisininas a white solid (72.7 mg). δ_(H) 8.91 (1H, s, OH), 7.28-7.91 (6H, m,Ar—H), 5.57 (1H, s, H-12), 3.11-3.19 (1H, m), 1.28-2.55 (11H, m), 1.51(3H, s, H-14), 1.04 (3H, d, J=5.96 Hz, H-16), 0.63 (3H, d, J=7.23 Hz,H-16).

EXAMPLE 6 Preparation of10α-(4′-thiomorpholino-1′-yl)-10-deoxo-10-dihydroartemisinin(10α-(thiomorpholino)dihydro-artemisinin) (Formula I: Y=thiomorpholino)

Reaction of bromide prepared from 10α-(trimethylsiloxy)dihydroartemisnin(356 mg, 1.00 mmol) as described in Example 3(b) above withthiomorpholine (300 μl, 3.00 mmol) afforded10α-(thiomorpholino)-dihydroartemisinin (243 mg, 66%) as a white solidafter flash chromatography (8% ethyl acetate/hexanes). M.p. 147.0-147.6°C.; [α]_(D) ²⁰ +17° (c 0.021/CHCl₃) ν_(max) (film) 2924, 2872, 1454,1418, 1376, 1326, 1278, 1226, 1198, 1184, 1154, 1130, 1100, 1056, 1038,1018, 988, 940, 926, 880, 850, 828, 756; δ_(H) 5.23 (1H, s, H-12), 3.93(1H, d, J=10.21 Hz, H-10), 3.20-3.28 (2H, m), 2.85-2.93 (2H, m),2.53-2.68 (5H, m), 2.25-2.36 (1H, m), 1.93-2.01 (1H, m), 1.78-1.86 (1H,m), 1.63-1.70 (2H, m), 1.14-1.52 (5H, m), 1.36 (3H, s, H-14), 0.90-1.04(1H, m), 0.91 (3H, d, J=6.14 Hz, H-16), 0.76 (3H, d, J=7.18 Hz, H-15);δ_(C): 103.70, 92.28, 91.42, 80.11, 51.54, 50.39, 45.66, 37.19, 36.14,34.12, 28.15, 25.84, 24.59, 21.44, 20.15, 13.41; m/z (CI, NH₃) 370(M⁺+1, 100), 324 (70), 310 (10): Anal. Calc. for C₁₉H₃₁NO₄S: C, 61.76;H, 8.46; N, 3.79%. found C, 62.04; H, 8.39; N, 3.65.

EXAMPLE 7 Preparation of10α-(4′-(S,S-dioxothiomorpholin-1′-yl)-10-deoxo-10-dihydroartemisinin(10α-(4′-morpholinosulphonyl)dihydroartemisinin) (Formula I:Y=4′-(S,S-dioxothiomorpholin-1′-yl) (4-morpholinosulphonyl)

To a solution of 10α-(4′-thiomorpholino)-10-deoxo-10-dihydroartemisinin(10α-(thiomorpholino)-dihydroartemisinin) (388 mg, 1.05 mmol) preparedas described in Example 6 above in dichloromethane (10 ml) at roomtemperature under nitrogen was added NMO (369 mg, 3.15 mmol), powderedmolecular sieve (525 mg, 4 Å) and TPAP (18.5 mg, cat.). The mixture wasstirred at room temperature overnight after which it was filteredthrough a pad of SiO₂ and the residue was washed with ethyl acetate(3×15 ml). The filtrate was concentrated in vacuo. The residue was thenpurified by flash chromatography (SiO₂; 35% ethyl acetate/hexanes) togive10α-(4′-(S,S-dioxothiomorpholin-1′-yl)-10-deoxo-10-dihydroartemisinin(10α-(4′-morpholinosulphonyl)dihydroartemisinin) as a white solid (421mg, 100%).

M.P. 152.3-152.7° C.; [α]_(D) ² +13° (c 0.035/CHCl₃) νmax (film) 2928,2872, 1454, 1378, 1308, 1270, 1228, 1198, 1124, 1040, 1018, 976, 940,878, 846, 826, 752, 704, 666; δ_(H): 5.27 (1H, s, H-12), 4.21 (1H, d,J=10.30 Hz, H-10), 3.18-3.46, (8H, m), 2.54-2.62 (1H, m), 2.28-2.36 (1H,m), 1.20-2.02 (9H, m), 1.35 (3H, s, H-14), 0.92-1.06 (1H, m), 0.93 (3H,d, J=5.99 Hz, H-15), 0.78 (3H, J=7.13 Hz, H-16); δ_(C): 174.20, 104.09,91.92, 90.84, 90.04, 51.74, 51.27, 46.88, 45.46, 37.29, 36.02, 34.04,28.91, 25.76, 24.66, 21.45, 20.10, 13.31; m/z (CI,NH₃) 402 (M⁺+1, 100),373 (30), 356 (64), 342 (16), 356 (20); Anal. Calc. for C₁₉H₃₁NO₆S: C,56.84; H, 7.78; N, 3.49. found: C, 56.83; H, 7.82; N, 3.37.

EXAMPLE 8 Preparation of10α-(4′-benzylpiperazin-1′-yl)-10-deoxo-10-dihydroartemisinin (FormulaI: Y=4′-benzyl-1′-piperazinyl)

Reaction of the bromide prepared from10β-(trimethylsiloxy)dihydroartemisinin (356 mg, 1.00 mmol) as describedin Example 3(b) with 1-benzylpiperazine (212.1 μl, 1.22 mmol) afforded10α-(4′-benzylpiperazin-1′-yl)-10-deoxo-10-dihydroartemisinin (144.3 mg,40%) as a white solid after flash chromatography (40% ethylacetate/hexane). M.p. 105-106° C.; [α]_(D) ²⁰ +10.3° (c. 0.909 CHCl₃)ν_(max) (film): 2954, 2920, 2860, 2802, 1494, 1454, 1376, 1344, 1294,1270, 1204, 1132, 1114, 1062, 1042, 1016, 986, 942, 924, 880, 852, 824,738, 694 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ_(H) 7.43-7.30 (5H, m, Ar—H),5.35 (1H, s, H-12), 4.10 (1H, d, J=10.2 Hz, H-10), 3.62 (1H, d, J=13.1Hz, benzylic-H), 3.55 (1H, d, J=13.1 Hz, benzylic-H), 3.11-3.06 (2H, m),2.80-2.70 (2H, m), 2.70-2.30 (7H, m), 2.15-2.02 (1H, m), 2.02-1.85 (1H,m), 1.85-1.70 (2H, m), 1.70-1.20 (9H, m), 1.20-1.00 (4H, m), 0.88 (3H,d, J=7.2 Hz, 6-methyl) ppm; ¹³C NMR (76 MHz, CDCl₃) δ_(C) 138.3, 129.13,128.1, 126.9, 103.8, 91.6, 90.4, 80.3, 63.1, 53.5, 51.7, 45.9, 37.4,36.3, 34.3, 28.5, 26.0, 24.8, 21.6, 20.3, 13.4 ppm; MS (CI, CH₄) m/e 443(M⁺+1, 10). Anal. Calcd. for C₂₆H₃₈N₂O₄: C, 7056, H, 8.65, N, 6.33.Found: C, 70.24, H, 8.67, N, 6.28.

EXAMPLE 9 Preparation of 10α-(2′-furyl)-10-deoxo-10-dihydroartemisinin(Formula I: Y=2-furyl)

Method 1:

To a solution of dihydroartemisinin (284 mg, 1.0 mmol) indichloromethane (10 mL) at 20° C. was added trichloroacetonitrile (2.0mL, 20.0 mmol) and one drop of 1,8-diazabicyclo[5.4.0]undecane. Themixture was stirred at 20° C. for 2 hours after which it wasconcentrated in vacuo at 20° C. The residue was then taken up indichloromethane (10 mL) at 0° C. and cooled to −40° C. The solution wastreated sequentially with furan (1.09 mL, 15.0 mmol) and borontrifluoride diethyl etherate (123 μl, 1.0 mmol), and the resultingmixture was stirred at −40° C. for another 30 min. The mixture wasquenched with saturated NaHCO₃ solution and extracted withdichloromethane (2×10 mL). The extracts were dried (MgSO₄) andconcentrated in vacuo. The residue was purified by flash chromatography(SiO₂; 15% ethyl acetate/hexanes) to give the captioned compound (11.0mg, 3.3%) as a colourless oil. Analytical sample was obtained fromrecrystallization from hexanes.

Method 2:

(a) Preparation of 10β-benzoyloxy-10-dihydroartemisinin(10β-dihydroartemisinyl benzoate)

To a solution of dihydroartemisinin (568 mg, 2.00 mmol) and benzoic acid(244 mg, 2.00 mmol) in tetrahydrofuran at 0° C. under nitrogen was addedtriphenylphosphine (524 mg, 2.00 mmol) and diethyl azodicarboxylate(ml). The mixture was allowed to warm to room temperature and stirredovernight. The solution was concentrated in vacuo. Flash chromatography(SiO₂; 10% ethyl acetate/hexanes) gave 10β-dihydroartemisinyl benzoateas a white solid (419 mg, 53%). M.p. 151.4-153.0° C.; [α]_(D) ²⁰ +119°(c 0.19/CHCl₃); ν_(max) (film): 2942, 2872, 1724, 1452, 1378, 1268,1176, 1114, 1064, 1024, 976, 902, 858, 832, 754, 712; δ_(H) 7.43-8.03(5H, m, Ar—H), 6.52 (1H, d, J=3.43, H-10), 5.58 (1H, s, H-12), 2.91-3.01(1H, m, H-9), 2.42 (1H, ddd, J=17.4, 13.3, 3.91 Hz), 1.33-2.10 (10H, m),1.45 (3H, s, H-14), 1.02 (3H, d, J=6.11 Hz, H-15), 0.98 (3H, d, J=7.35Hz, H-14); δ_(C): 165.31, 133.03, 129.96, 129.48, 128.39, 104.30, 95.29,88.66, 88.63, 80.42, 52.27, 43.84, 37.44, 36.10, 34.43, 29.98, 25.78,24.50, 24.25, 20.14, 12.50; m/z (EI): 388 (M⁺).

(b) Preparation of 10α-(2′-furyl)-10-deoxo-10-dihydroartemisinin(Formula I: Y=2-furyl)

A solution of 10β-benzoyloxy-10-dihydroartemisinin (193 mg, 0.50 mmol)in dichloromethane (5 mL) at −45° C. was treated sequentially with furan(542 μl, 7.5 mmol) and boron trifluoride diethyl etherate (123 μl, 1.0mmol). The resulting mixture was stirred at −45° C. for another 1 hr.The mixture was quenched with saturated NaHCO₃ solution and extractedwith dichloromethane (3×10 mL). The extracts were dried (MgSO₄) andconcentrated in vacuo. The residue was purified by flash chromatography(SiO₂; 15% ethyl acetate/hexanes) to give the captioned compound (53.7mg, 32%) as a colourless oil.

M.p. 96-97° C.; ¹H NMR (300 MHz, CDCl₃) δ_(H) 7.38 (1H, m, H-5′),6.34-6.30 (2H, m, H-3′ & H-4′), 5.38 (1H, s, H-12), 4.46 (1H, d, J=10.9Hz, H-10), 2.84 (1H, m), 2.60-2.20 (2H, m), 2.20-1.20 (9H, m), 1.20-0.80(6H, m), 0.62 (3H, d, J=7.2 Hz, 6-methyl) ppm; ¹³C NMR (76 MHz, CDCl₃)δ_(C) 153.2, 142.0, 110.0, 108.3, 104.2, 92.2, 80.4, 76.6, 71.1, 52.0,45.7, 37.4, 36.3, 34.1, 31.5, 26.1, 24.7, 21.3, 20.3, 13.7 ppm; MS (CI,CH₄) m/e 335 (M⁺+1, 43).

EXAMPLE 10 Preparation of10α-(Pyrrol-2′-yl)-10-deoxo-10-dihydroartemisinin (Formula I:Y=2-pyrrolyl)

A solution of 10β-benzoyloxy-10-deoxoartemisinin (700.8 mg, 1.80 mmol)prepared as described in Example 9, Method 2(a) in dichloromethane (30mL) at −50° C. was treated sequentially with pyrrole (624 μl, 9.00 mmol)and boron trifluoride diethyl etherate (332 μl, 2.70 mmol), and thenstirred at −50° C. for 1 hr. The mixture was quenched with saturatedNaHCO₃ solution, and extracted with dichloromethane (3×10 mL). Theextracts were dried (MgSO₄) and concentrated in vacuo. The residue waspurified by flash chromatography (SiO₂; 30% diethyl ether/hexanes) togive the captioned compound (486.6 mg, 81%) as a colourless oil. [β]_(D)²⁰ +198.70 (c 0.105 CHCl₃); ν_(max) (film): 2924, 2854, 1460, 1376,1066, 1024, 722 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ_(H) 8.80 (1H, br s, NH),6.71 (1H, m, H-5′), 6.04 (2H, m, H-3′ & H-4′), 5.39 (1H, s, H-12), 4.47(1H, d, J=10.8 Hz), 2.58 (1H, m), 2.50-2.10 (2H, m), 2.10-1.95 (1H, m),1.93 (1H, m), 1.80-1.68 (2H, m), 1.68-1.15 (7H, m), 1.15-0.80 (4H, m),0.93 (3H, d, J=7.1 Hz, 6-methyl) ppm; ¹³C NMR (76 MHz, CDCl₃) δ_(C)129.9, 117.6, 107.2, 106.7, 104.1, 91.9, 80.5, 71.9, 60.2, 51.8, 45.7,37.2, 36.2, 34.0, 32.9, 25.9, 24.6, 21.2, 20.1, 14.0, 13.9 ppm; MS (CI,butane) m/e 334 (M⁺+1, 100). Anal. Calcd. for C₁₉H₂₇NO₄: C, 68.44, H,8.16, N, 4.20. Found: C, 68.77, H, 8.56, N, 3.85.

EXAMPLE 11 Preparation of10α-(4′-Benzyl-4′-methylpiperazinium-1′-yl)-10-deoxo-10-dihydroartemisininIodide Salt (Formula I: Y=4′-benzyl-4′-methylpiperazinium-1′-yl)

A solution of10α-(4′-benzylpiperazin-1′-yl)-10-deoxo-10-dihydroartemisinin (272 mg,0.62 mmol) prepared as described in Example 8 above in a mixture ofdichloromethane (1.8 mL) and diethyl ether (5.4 mL) under nitrogenatmosphere at 0° C. was treated dropwise with iodomethane (36.7 μl, 0.59mmol). The mixture was agitated and allowed to warm to 20° C. graduallyovernight. The precipitate was collected and washed with diethyl ether(2×5 mL) and dried in high vacuum. It was further purified byrecrystallization from methanol/diethyl ether to yield rectangular-plateshaped crystals (87 mg, 24%). M.p. 159-161° C.; [α]_(D) ²⁰ +18.4° (c0.436 CHCl₃) ν_(max) (film): 3448, 2928, 2196, 1457, 1378, 1210, 1133,1099, 1041, 982, 918, 880, 852, 828, 766, 732, 642 cm⁻¹; ¹H NMR (300MHz, CDCl₃) ä_(H) 8.00-7.60 (2H, d, J=6.2 Hz, H-2″ & H-6″), 7.60-7.35(3H, m, Ar—H), 5.32 (1H, s, H-12), 5.25-5.05 (2H, m, benzylic-H), 4.13(1H, d, J=10.2 Hz, H-10), 3.95-3.55 (4H, m), 3.55-2.90 (9H, m),2.65-2.20 (2H, m), 2.20-1.15 (14H, m), 1.15-0.87 (4H, m), 0.80 (3H, d,J=6.9 Hz, 6-methyl) ppm; ¹³C NMR (76 MHz, CDCl₃) ä_(C) 133.4, 130.6,129.1, 126.5, 104.0, 91.5, 90.1, 80.1, 67.4, 59.5, 59.3, 51.5, 45.5,37.2, 36.1, 34.0, 28.4, 25.9, 24.5, 21.5, 20.1, 13.3 ppm

EXAMPLES 12 TO 61

By processes similar to those described in Examples 1 to 11 above,further compounds according to the invention were prepared as detailedin Table I below. In this table the compounds are identified byreference to formula I. TABLE I Ex. No. Y R¹ R² Physical data 122,4,6-(-OCH₃)₃ — — White foam. [α]_(D) ^(20.5) +49.51°(c. 0.053 inphenyl CHCl₃) ν_(max), (Neat) 2936, 2872, 1608, (mixture of 1496, 1456,1420, 1374, 1330, 1278, 1224, isomers) 1204, 1152, 1120, 1050, 1040,974, 954, 930, 902, 880, 856, 834, 814, 734, 702 cm⁻¹: δ_(H)6.10-6.18(2H, m, Ar-H), 5.46(1H, s, H12) , 5.38(1H, s, H-12′), 5.31(1H,d, J=10.4 Hz, H-10), 5.07(1H, d, J= 10.9 Hz, H-10′), 3.88, 3.81, 3.80,3.76 (OMe), 3.36-3.42(1H, m), 2.35-2.41(1H, m), 1.05-2.15(10H, m),1.63(3H, s, J=6.27 Hz, H-16′), 0.88-0.93(3H, m, H-15 & H-16), 0.58(3H,d, J=7.26 Hz, H-15′), m/z(CI, NH₃) 452(M+NH₄ ⁺, 4%), 436(16), 435(M⁺+1,12), 419(100), 389 (74), 347(28). Anal. Calc. for C₂₄H₃₄O₇: C, 66.36; H,7.83; Found: C, 66.42; H, 7.89 13 2-naphthyl — — White solid. M.p.145-146° C.; [α]_(D) ^(20.5) : (10β-isomer) −67.8°(c 0.027/CHCl₃;ν_(max)(film) 2950, 2874, 1510, 1452, 1376, 1208, 1106, 1074, 1040,1010, 954, 936, 886, 854, 824, 786, 750; δ_(H) 7.80-7.85(5H, m, Ar-H),7.42-7.51(3H, m, Ar-H), 5.93(1H, d, J= 6.59 Hz, H-10), 5.67(1H, s,H-12), 2.81-2.94(1H, m, H-9), 2.33-2.48(1H, m), 0.86-2.13(10H, m),1.42(3H, s, H-14)., 1.02(1H, d, J=6.09 Hz, H-16), 0.55 (1H, d, J=7.66Hz, H-15); δ_(C) 134.85, 127.82, 127.42, 127.12, 125.65, 125.17, 124.84,124.26, 90.92, 73.04, 51.48, 43.44, 37.48, 36.64, 34.15, 32.10, 25.69,24.89, 24.77, 19.85, 13.65; m/z(CI, CH₄) 395(M⁺+1, 16%), 394(M+, 32),362(44) 349(84), 331(16), 304(20), 291(26) 182(100), 168(60). Anal.Calcd. for C₂₅H₃₀O₄: C, 76.11; H, 7.66; found: C, 76.24; H, 7.69. 142-OCH₃phenyl — — Colourless oil. δ_(H) 6.83-7.50(4H, m, (10β-isomer)Ar-H), 5.94(1H, d, J=4.65 Hz, H-10), 5.58(1H, s, H-12), 3.84(3H, s,OCH₃), 2.86-2.99(1H, m, H-9), 2.30-2.40(1H, m), 1.19-2.11(10H, m),1.39(3H, s, H-14), 1.01(1H, d, J=5.77 Hz, H-16) 0.43(1H, d, J=7.64 Hz,H-15); δ_(C) 134.85, 127.00, 126.37, 120.02, 109.19, 90.86, 68.63,55.19, 51.30, 43.39, 37.53, 36.72, 34.21, 29.87, 25.68, 24.97, 24.75,19.83, 13.45; m/z(CI, CH₄) 375(M³⁰ +1, 12%), 374(M⁺, 16), 342(100),329(48) 311(14), 284(28), 182(56), 148(76) 137(60), 121(48). Anal. Calc.for C₂₂H₃₀O₅: C, 70.56; H, 8.07; Found C, 70.78; H, 8.28 15 —NR¹R² —Hphenyl White solid. M.p. 159-160° C.; [α]_(D) ²⁰ (10β-isomer) −51.4° (c0.35/CHCl₃); ν_(max)(film) 3348, 2924, 2872, 1604, 1502, 1444, 1376,1314, 1270, 1196, 1152, 1116, 1098, 1040, 1012, 994, 944, 926, 878, 856,826, 748, 690; δ_(H) 7.17-7.22(2H, m, Ar-H), 6.75-6.87(3H, m, Ar-H),5.45(1H, s, H-12), 4.85(1H, dd, J=9.86, 9.81 Hz, H-10), 4.32(1H, d,J=9.81 Hz, NH), 2.49-2.61(1H, m, H-9), 2.35-2.45(1H, m), 2.00-2.08(1H,m), 1.74-1.92(4H, m), 1.26-1.65(7H, m), 1.42(3H, s, H-14), 1.05-1.10(1H,m), 1.01(3H, d, J=6.18 Hz, H-16), 0.95(3H, d, J=7.18 Hz, H-15); δ_(C)128.99, 118.56, 114.02, 91.08, 80.70, 80.39, 51.71, 45.76, 37.18, 36.26,34.03, 32.71, 25.97, 24.60, 21.79, 20.17, 13.80; m/z(CI, CH₄) 360(M³⁰+1, 56%), 359 (M+, 56), 342(98), 324(20), 314(100) 296(98), 267(50),249(22), 221(80) 163(40), 133(100), 94(38). Anal. Calc. for C₂₁H₂₉NO₄:C, 70.17; H, 8.13; N, 3.90; Found: C, 70.25; H, 8.24; N, 3.73 16 —N¹R²—H 4-F phenyl White solid. M.p. 170.1° C.; ν_(max) (Nujol) (10α-isomer)3358(ν_(NH)), 2924, 2854, 1512, 1460, 1378, 1264, 1216, 1194, 1116,1099, 1046, 1022, 942, 924, 880, 846, 832, 810, 780 cm⁻¹, δ_(H)6.66-6.92(4H, m, Ar-H), 5.44(1H, s, H-12), 4.76(1H, dd, J=10.0, 10.0 Hz,H-10), 4.32(1H, d, J=10.0 Hz, NH), 2.49-2.61(1H, m, H-9), 2.40(1H, ddd,J= 17.3, 13.4, 3.93 Hz), 2.05(1H, ddd, J= 14.6, 4.79, 3.07 Hz),1.05-1.97(9H, m), 1.42(3H, s, H-14), 1.00(3H, d, J= 6.11 Hz, H-16),0.95(3H, d, J=7.18 Hz, H-15); δ_(C) 141.95, 115.34(d, J=17.7 Hz),115.15(d, J=2.69 Hz), 104.13, 91.10(d, J=2.22 Hz), 81.41, 80.41, 51.69,45.73, 37.29, 36.25, 34.01, 32.60, 25.94, 24.60, 21.79, 20.17, 13.81;m/z (CI, CH₄) 378(M³⁰ +1, 44%), 377(M⁺, 100) 358(70), 314(14), 267(26),221(18), 163(34), 151(42), 111(6) . Anal. Calc. for C₂₁H₂₈FNO₄: C,66.82; H, 7.48; N, 3.71; Found C, 67.06; H, 7.60; N, 3.51 17 —NR¹R² —H4-Cl phenyl White solid. M.p. 179.0° C.; [α]_(D) ²⁰ −63.5° (10α-isomer)(c 0.20/CHCl₃) ; ν_(max)(film): 3346, 2926, 2874, 1604, 1514, 1494,1454, 1378, 1268, 1196, 1152, 1094, 1040, 1012, 992, 944, 926, 878, 818,756; δ_(H) 7.09-7.14(2H, m, Ar-H), 6.66-6.71(2H, m, Ar-H), 5.44(1H, s,H-12), 4.78(1H, brs, H-10), 4.42(1H, brs, NH), 2.49-2.61(1H, m, H-9),2.40 (1H, ddd, J=17.4, 13.5, 3.98 Hz), 2.05 (1H, ddd, J=14.6, 4.78, 3.12Hz), 1.05-1.97(9H, m), 1.41(3H, s, H-14), 1.00(3H, d, J=6.12 Hz, H-16),0.94 (3H, d, J=7.18 Hz, H-15); δ_(C) 144.31, 128.76, 123.20, 115.28,104.15, 91.09, 80.76, 80.38, 51.66, 45.67, 37.28, 36.23, 33.99, 32.56,25.93, 24.59, 21.78, 20.16, 13.73; m/z(CI, CH₄) 393(M³⁰ +1, 16%), 376(8), 347(20), 330(16), 247(10), 221 (16), 167(100), 127(8). Anal. Calc.for C₂₁H₂₈ClNO₄: C, 64.03; H, 7.16; N, 3.55; Found C, 64.16; H, 7.40; N,3.45. 18 —NR¹R² —H 4-Br phenyl White solid. M.p. 183.1° C.; [α]_(D) ²⁰−60.0° (10α-isomer) (c 0.23/CHCl₃) ν_(max)(film) 3348, 2924, 2872, 1598,15H, 1492, 1452, 1378, 1268, 1196, 1152, 1122, 1094, 1040, 1012, 992,926, 878, 816, 756; dH 7.20-7.25(2H, m, Ar-H), 6.61-6.66(2H, m, Ar-H),5.44(1H, s, H-12), 4.78(1H, dd, J=10.0, 9.95 Hz, H-10), 4.48(1H, d,J=10.0 Hz, NH), 2.49-2.61(1H, m, H-9), 2.40(H, ddd, J= 14.0, 13.7, 3.87Hz), 1.05-2.08(10H, m), 1.41(3H, s, H-14),1.00(3H, d, J= 6.07 Hz, H-16),0.94(3H, d, J=7.15 Hz, H-15); δ_(C) 144.79, 131.61, 115.76, 110.32,104.17, 91.09, 80.65, 80.39, 51.67, 45.67, 37.29, 36.24, 33.99, 32.54,25.92, 24.60, 21.78, 20.17, 13.71; m/z(CI, CH₄) 439(M³⁰ +1, 12%),422(14), 392(100), 376 (36), 267(14), 221(50), 154(34) Anal. Calc. forC₂₁H₂₈BrNO₄: C, 57.54; H, 6.44; N, 3.19; Found: C, 57.81; H, 6.64; N,3.14. 19 —NR¹R² —H 4-I phenyl White solid. [α]_(D) ²⁰ −68.8°(c(10α-isomer) 0.16/CHCl₃) ; ν_(max)(film) 3346, 2924, 1592, 1510, 1454,1378, 1268, 1196, 1040, 994, 926, 878, 818, 754; δ_(H) 7.36-7.41(2H, m,Ar-H), 6.51-6.56(2H, m, Ar-H), 5.43(1H, s, H-12),4.78(1H, dd, 7 =10.0,9.97 Hz, H-10), 4.56(1H, d, J=10.0 Hz, NH), 2.34-2.56(2H, m, H-9),1.05-2.08 (10H, m), 1.41(3H, s, H-14), 1.00(3H, d, J=6.04 Hz, H-16),0.93(3H, d, J= 7.13 Hz, H-15); ₆₇ _(C) 145.46, 137.45, 116.35, 104.18,91.09, 80.46, 79.59, 51.66, 45.66, 37.29, 36.25, 34.00, 32.50, 25.91,24.61, 21.79, 20.19, 13.71; m/z (CI, CH₄) 486(M⁺_(+1, 4%), 485(M+, 6), 468) (12), 440(100), 422(34), 267(6), 259 (20),221(20). Anal. Calc, for C₂₁H₂₈INO₄: C, 51.97; H, 5.81; N, 2.89; Found:C, 52.22; H, 5.83; N, 2.57. 20 —NR¹R² —H 4-biphenyl White solid. [α]_(D)²⁰ −76.5°(c (10α-isomer) 0.51/CHCl₃) ν_(max)(film) 3348, 2924, 2872,16H, 1528, 1488, 1446, 1378, 1268, 1268, 1196, 1152, 1128, 1040, 1012,992, 926, 878, 826, 760, 698; δ_(H) 7.25-7.58(7H, m, Ar-H),6.82-6.87(2H, m, Ar-H), 5.49(1H, s, H-12), 4.90(1H, dd, J=9.85, 9.85 Hz,H-10), 4.50(1H, d, J=9.85 Hz, NH), 2.36-2.62(2H, m), 1.07-2.09(10H, m),1.44(3H, s, H-14), 1.02(3H, d, J=6.12 Hz, H-16), 0.98(3H, d, J=7.17 Hz,H-15); δ_(C) 145.22, 141.16, 131.53, 128.45, 127.71, 126.29, 125.98,114.30, 104.14, 91.14, 80.67, 80.42, 51.72, 45.76, 37.30, 36.27, 34.04,21.68, 25.98, 24.62, 21.81, 20.19, 13.81; m/z(CI,CH₄) : 436(M⁺+1, 2%),412(100), 395(42), 379(8), 284 (2), 267(2), 170(2). Anal. Calc. forC₂₇H₃₃NO₄: C, 74.45; H, 7.64; N, 3.22; Found: C, 73.51; H, 7.67; N,3.12. 21 —NR¹R² —H benzyl White solid. [α]_(D) ²⁰ −26.7°(c 0.15/CHCl₃);(10α-isomer) ν_(max)(film) 3348, 2924, 2870, 1452, 1376, 1158, 1116,1056,1042, 10H, 992, 942, 926, 878, 828, 736, 700; δ_(H) 7.21-7.42 (5H,m, Ar-H), 5.32(1H, s, H-12), 4.17 (1H, d, J=13.9 Hz, H-1′), 4.13(1H, d,J=9.63 Hz, H-10), 3.97(1H, d, J=13.9 Hz, H-1′), 2.29-2.45(2H, m),2.29(1H, brs, NH), 2.01-2.09(1H, m), 1.86-1.95 (1H, m), 1.65-1.78(2N,m), 1.44-1.59 (2N, m), 1.48(3H, s, H-14), 1.22-1.40 (3N, m),0.91-1.09(1H, m), 0.97(3N, d, J=5.94 Hz, H-16), 0.96(3H, d, J=7.14 Hz,H-15); δ_(C) 140.82, 128.03, 127.84, 126.45, 103.91, 91.39, 85.68,80.65, 51.69, 48.21, 45.86, 37.24, 36.29, 34.07, 32.77, 26.07, 24.63,21.73, 30.19, 14.12; m/z (CI, CH₄) 374(M⁺+1, 100%), 356(54) 338(42),328(38), 309(12), 253(16) 221(10), 119(16). Anal. Calc. for C₂₂N₃₂NO₄:C, 70.75; N, 8.37; N, 3.75; Found; C, 70.78; H, 8.82; N, 3.75. 22 —NR¹R²—H 2-F benzyl White solid. M.p. 47.4-48.7° C., [α]_(D) ²⁰ (10α-isomer)−16.9°(c 1.46/CHCl₃); ν_(max)(film) 3336, 2924, 2872, 1584, 1486, 1454,1376, 1226, 1196, 1158, 1116, 1056, 1042, 1014, 994, 926, 878, 826, 756;δ_(H) 6.99-7.50(4H, m, Ar-H), 5.34(1H, s, H-12), 4.21(1H, d, J= 14.5 Hz,H-1′), 4.15(1H, 6, J=6.72 Hz, H-10), 3.99(1H, d, J=14.5 Hz, H-1′),2.35-2.45(2H, m), 0.90-2.08(10H, m), 1.47(3H, s, H-14), 0.98(3H, d, J=5.99 Hz, H-16), 0.94(3H, d, J=7.16 Hz, H15); δ_(C) 129.83(d, J=4.79 Hz),127.94 (d, J=8.05 Hz), 123.64(d, J=3.40 Hz), 114.89(d, J=21.6 Hz),103.90, 91.35, 86.03, 80.59, 51.69, 45.86, 41.96 (d, J=3.53 Hz), 37.26,36.28, 34.08, 32.66, 26.02, 24.62, 21.72, 20.17, 14.00; δ_(F) −120;m/z(CI, CH₄) 392(M⁺+1, 24%) 374(46), 346(100), 328(34), 267(2), 221(4),209(6), 165(82), 154(50), 109(42). Anal. Calcd. for C₂₂H₃₀NO₄F: C,67.50; H, 7.72; N, 3.58; found C, 67.75, H, 7.92; N, 3.49. 23 —NR¹R² —H3,5-(CF₃)₂ benzyl Colourless oil. M.p. 51.0-52.8° C.; [α]_(D) ²⁰(10α-isomer) −27°(c 0.027 CHCl₃) δ_(H) 7.88(2H, brs, Ar-H), 7.55(1H,brs, Ar-H), 5.31(1H, s, H-12), 4.24(1H, d, J=15.1 Hz, H-1′), 4.12(1H, d,J=15.1 Hz, H-1′), 4.06(1H, d, J=9.82 Hz, H-10), 2.34-2.45(2H, m),0.90-2.09(10H, m), 1.47(3H, s, H-14), 0.98(3H, d, J=7.26 Hz, H-15),0.97(3H, d, J=4.94 Hz, H16); δ_(F) −64.1; m/z(CI, CH₄) 510(M³⁰ +1, 48%),490(100), 464(74), 441(38), 283(24), 267(30), 244(10) 221(20), 163(22).Anal. Calc. for C₂₄H₂₉NO₄F₆: C, 56.58; H, 5.74; N, 2.75; Found: C,56.75; H, 5.76; N, 2.70. 24 —NR¹R² —H —^(n)C₃H₇ White solid. M.p.96.1-97.3° C. (changed (10α-isomer) colour before melting); [α]_(D) ²⁰+24.8°(c 0.33/CHCl₃) ν_(max)(film) 3304, 2952, 2924, 2870, 1492, 1454,1378, 1208, 1160, 1118, 1042, 1012, 974, 942, 922, 878, 844, 828, 754;δ_(H) 5.31(1H, s, H-12), 4.11(1H, d, J=9.78 Hz, H-10), 2.95(1H, ddd, J=11.4, 8.07, 6.55 Hz, CH₂NH), 2.61(1H, ddd, J=11.4, 8.07, 6.45 Hz,CH₂NH), 2.26-2.43(2H, m), 2.03(1H, ddd, J= 14.5, 4.54, 2.49 Hz),1.84-1.93(1H, m), 1.00-1.83(10H, m), 1.44(3H, s, H-14) 0.97(3H, d,J=6.10 Hz, H-16), 0.92 (3H, t, J=7.36 Hz, CH₃), 0.89(3H, d, J= 7.18 Hz,H-15); δ_(C) 103.82, 91.34, 86.17, 51.69, 46.27, 45.88, 37.27, 36.27,34.10, 32.49, 26.04, 24.61, 23.49, 21.72, 20.19, 14.03, 11.62; m/z(CI,CH₄) 326 (M⁺+1, 100%), 308(56), 280(48), 221 (16), 163(18). Anal. Calcd.for C₁₈H₁₃NO₄: C, 66.43; H, 9.60; N, 4.36; Found: C, 66.17, H, 9.68; N,4.20. 25

— — White solid. M.p. 121.2° C.; [α]_(D) ²⁰ +15.3°(c 0.30/CHCl₃);ν_(max)(film) 2924, 2850, 1450, 1376, 1294, 1258, 1202, 1158, 1110,1056, 964, 930, 880, 846, 826, 744;δ_(H 5.29(1H, s, H-12), 3.99(1H, d, J=10.23 Hz, H-10), 3.63-3.76(4H, m, O(CH)₂)₂), 2.96-3.03(2H, m, CH ₂NCH ₂) 2.64-2.71(2H, m, CH ₂NCH ₂),2.53-2.61(1H, # m, H-9), 2.31-2.41(1H, m), 1.00-2.06 (10H, m), 1.41(3H,s, H-14), 0.96(3H, d, J=6.14 Hz, H-16), 0.83(3H, d, J=7.18 Hz, H-15);δ_(C) 103.74, 91.48, 90.51, 80.16, 67.25, 51.57, 47.52, 45.66, 37.25,36.16, 34.14, 28.04, 25.84, 24.62, 21.50, 20.14, 13.25; m/z(EI) 353(M+,6), 294 (4), 236(4), 221(16), 209(12), 163 (14), 127(32), 116(100),88(24) Anal. Calcd. for C₁₀H₃₁NO₅: C, 64.56; H, 8.84; N, 3.96%; Found: #C, 64.67; H, 9.10; N, 3.90. 26 —NR¹R² —C₂H₅ —C₂H₅ White solid. δ_(H)5.37(1H, s, H-12), 4.76 (10α-isomer) (d, J=7.54 Hz, H-10), 2.80-3.03(4H,m, N(CH ₂CH₃)₂), 2.29-2.44(1H, m, H-9), 0.94-1.89(11H, m), 1.53(3H, s,H-14), 1.14(6H, dd, J=7.20, 7.12 Hz, N(CH₂CH ₃)₂), 1.04(3H, d, J=7.23Hz, H-15), 0.91(3H, d, J=5.72 Hz, H-16) 105.33, 96.11, 81.43, 51.68,45.23, 41.48, 35.12, 34.52, 33.96, 29.56, 23.77, 22.24, 21.88, 18.52,15.56, 11.50. m/z(CI, CH₄) 340(M³⁰ +1, 52%), 251 (100), 221(26) 27

— — White solid. M.p. 147.8-148.2° C.; [α]_(D) ^(20 −11.6°(c 0.19/CHCl)₃); ν_(max)(film) 2926, 2872, 1606, 1488, 1462, 1376, 1258, 1200, 1158,1126, 1040, 1010, 926, 880, 828, 746, 718; δ_(H) 7.03-7.09(2H, m, Ar-H),6.60-6.71(2H, m, Ar-H), 5.44(1H, s, H-12), 4.98(1H, d, J=10.4 Hz, H-10),3.79(1H, apparent dt, J=10.4, 9.08 Hz, # ArCH ₂), 3.56(1H, apparent dt,J=9.08, 4.36 Hz, ArCH ₂), 2.94-3.12(2H, m, NCH ₂), 2.67-2.79(1H, m,H-9), 2.39(1H, ddd, J=14.3, 13.3, 3.94 Hz), 2.03(1H, ddd, J=14.5, 4.73,2.97 Hz), 1.75-1.95(4H, m), 1.06-1.69(6H, m), 1.38(3H, s, H-14),1.00(3H, d, J=6.17 Hz, H-15), 0.94(3H, d, J=7.15 Hz, H-15); 150.51,130.18, 126.92, 124.57, 118.19, # 107.47, 103.90, 91.46, 81.53, 80.05,51.58, 45.61, 44.83, 37.28, 36.20, 34.12, 29.75, 27.99, 25.83, 24.61,21.51, 20.16, 13.30; m/z(CI, CH₄) 386 (M⁺+1, 100), 340(50), 326(14),267(6) Anal. Calcd. for C₂₂H₃₁NO₄; C, 71.66; H, 8.10; N, 3.63; Found: C,71.45; H, 8.07; N, 3.57. 28

— — White solid. M.p. 125.3-126.6° C.: [α]_(D) ^(20 +14.7°(c 0.19/CHCl)₃); ν_(max)(film) 2924, 2870, 1452, 1376, 1278, 1200, 1154, 1130, 1100,1040, 10H, 982, 926, 880, 828, 742; δ_(H) 7.07-7.15(4H, m, Ar-H), 5.36(1H, s, H-12), 4.26(1H, d, J=10.2 Hz, H-10), 4.20(1H, d, J=15.2 Hz, ArCH₂N), 3.97(1H, d, J=15.2 Hz, ArCH ₂N), 3.26-3.36(1H, m, ArCH ₂), #2.70-3.00(4H, m, 3H-CH ₂CH ₂N & 1H), 2.40(1H, ddd, J=14.4, 13.6, 3.93Hz), 2.00-2.07(1H, m), 1.86-1.95(1H, m), 1.71-1.81(2H, m), 1.19-1.65(4H,m), 1.41(3H, s, H-14) 1.02-1.12(1H, m), 0.99(3H, d, J=6.09 Hz, H-16),0.87(3H, d, J=7.19 Hz, H-15); δ_(C) 135.74, 134.94, 128.55, 126.59,125.45, 125.21, 103.76, 91.61, 90.60, 80.31, 51.64, 49.18, 45.82, 45.65,37.29, 36.21, 34.20, 29.89, 28.66, 25.88, 24.67, # 21.53, 20.19, 13.46;m/z(CI, CH₄) 400 (M³⁰ +1, 100), 398(22), 354(54), 340 (20), 267(4),162(44), 134(14) Anal. Calc. for C₂₄H₃₃NO₄: C, 72.15; H, 8.33; N, 3.51:Found: C, 71.98; N, 8.36; N, 3.36. 29 —NR¹R² —H —CH(CH₃)phenyl Whitesolid. M.p. 55.4-57.5° C.; δ_(H) (10α, 1′S-isomer) 7.20-7.42 (SN, m,Ar-H), 5.13(1H, a, H-12), 4.45(1H, q, J=6.62 Hz, H-1′), 3.77(1H, d,J=9.79 Hz, H-10), 2.23-2.43(2H, m), 2.03(1H, ddd, J= 14.5, 4.73, 3.08Hz), 0.96-1.88(9H, m), 1.48(3H, s, H-14), 1.31(3H, d, J=6.62 Hz, CH ₃),0.91(3H, d, J=5.94 Hz, H-16), 0.91(3H, d, J=7.14 Hz, H-15); δ_(C)146.07, 128.01, 126.96, 126.39, 103.81, 91.38, 83.80, 80.70, 52.37,51.71, 45.82, 37.08, 36.30, 33.95, 33.40, 26.11, 25.S3, 24.57, 21.64,20.14, 14.22; m/z(CI, CH₄) 388(M³⁰ +1, 100%), 370(22) 342(64), 267(8),221(10). Anal. Calc. for C₂₃H₃₃NO₄: C,71.29; H, 8.58; H, 3.61; Found C,71.20; H, 8.72; H, 3.62. 30 —NR¹N² —H —CH(CH₃)phenyl White solid. δ_(H)7.20-7.43(5H, m, Ar-H), (10α,1′R-isomer) 5.36(1H, s, H-12), 4.44(1H, q,J=6.41 Hz, H-1′), 4.31(1H, d, J=9.70 Hz, H-10), 2.21-2.40(2H, m),2.00-2.08(1H, m), 1.02-1.95(9H, m), 1.45(3H, s, H-14), 1.31(3H, d,J=6.41 Hz, CH ₂), 0.99(3H, d, J=6.18 Hz, H-15), 0.93 (3H, d, J=7.16 Hz,H-15); δ_(C) 147.01, 128.06, 127.01, 126.59, 103.85, 91.33, 83.03,80.56, 51.72, 51.51, 45.92, 37.29, 36.28, 34.14, 33.09, 26.01, 24.66,22.35, 21.83, 20.21, 14.22; m/z(CI, CH₄) 388 (M⁺+1, 100%), 370(56),342(42), 309 (30), 267(18), 253(32), 221(20), 119 (34) 31 —NR¹N² —H—CH(CO—OCH₃)phenyl Colourless oil. ν_(max)(Neat): 3342(ν_(NH))(10α,1′R-isomer) 2926, 2827, 1742(ν_(C═O), ester), 1602, 1494, 1452,1376, 1246, 1198, 1158, 1130, 1042, 10H, 994, 928, 880, 844, 826, 736,700 cm⁻¹; ¹H nmr(300 MHz, CDCl₃) δ_(H) 7.21- 7.50(5H, m, Ar-H), 5.13(1H,s, H-12), 4.94(1H, s, H-2′), 3.85(1H, d, J=9.81 Hz, H-1a), 3.65(3H, s,OMe), 2.74(1H, br.s., NH), 2.35(1H, m, H-9), 1.05-2.07 (11H, m, H-2 ±2,H-3±2, H-4, H-5, H-6± 2, H-7±2, H-8), 1.47(3H, s, 1-CH₃), 0.90(6H, d±2,signals overlap, 5-CH₃, 9-CH₃) ppm; m/z(CI, CH₄) 432(M⁺+1, 96%),386(100), 372(44), 312(14), 267(24), 221(28), 166(96). Anal. Calcd. forC₂₄H₃₃NO₆: C, 66.80; H, 7.71; H, 3.24; Found: C, 66.98; H, 7.53; H,3.05. 32 —NR¹N² —H —CH(CO—OCH₃)phenyl ¹H nmr(300 MHz, CDCl₃) δ_(H)7.28-7.51(5H, (1α,1′S-isomer) m, Ar-H), 5.22(1H, s, H-12), 5.04(1H, s,H-2′), 4.28(1H, d, J=9.81 Hz, H-10). 3.68(3H, s, OMe), 2.57(1H, br.s.,NH), 2.29-2.44(1H, m, H-9), 0.96-2.44(1H, m, H-2±2, H-3±2, H-4, H-5,H-6±2, H-7± 2, H-8), 1.43(3H, s, 1-CH₃), 0.97(3H, d, J=6.11 Hz. H-15),0.90(3H, d, J=7.16 Hz, H-15)ppm; m/z(CI, CH₄) 432(M⁺+1, 90%), 386(100),372(50) 33 —NR¹N² —H 4-(CO—OCH₃)phenyl White solid. M.p. 117.7-118.5°C.; [α]_(D) ²⁰ (10α-isomer) −84.1(c 0.82/CHCl₃); ν_(max)(film) 3344,2948, 1710, 1608, 1528, 1434, 1378, 1270, 1178, 1110, 1040, 1012, 926,878, 842, 768; δ_(H)6.66-7.76(4H, m, Ar-H) 5.46 (1H, s, H-12), 5.06(1H,d, J=9.96 Hz, NH), 4.88(1H, dd, J=9.89, Hz, H-10) 3.83(3H, s, OMe),2.56-2.60(1H, m), 2.33-2.42 (1H, m), 0.85-2.04(10H, m), 1.39(3H, s,H-14), 0.99(3H, d, J=6.09 Hz, H-15), 0.92(3H, d, J=7.11 Hz, H-16; δ_(C):167.06, 149.99, 131.04, 119.64, 113.01, 104.30, 91.21, 80.49, 80.02,51.70, 51.40, 45.67, 37.34, 36.20, 34.04, 32.50, 25.92, 24.66, 21.84,20.94, 20.22, 14.10, 13.67; m/z(CI, CH₄) 418(M³⁰ +1, 32), 400(6),372(100), 358(8), 221(28) 152(26). Anal. Calc. for C₂₂H₃₁NO₄: C, 66.17;H, 7.48; H, 3.35; round: C, 65.57; H, 7.57; H, 3.36. 34 —NR¹N² —Hcyclopentyl White solid. M.p. 114.1-114.9° C.; [α]_(D) ²⁰ (α-isomer)−1.6°(c 0.98/CHCl₃); ν_(max)(film) 3314, 2950, 2870, 1446, 1376, 1198,1154, 1114, 1098, 1042, 1014, 976, 944, 924, 878, 860, 826, 754; δ_(H):5.29(1H, s, H-12) 4.08(1H, d, J=9.76 Hz, H-10), 3.52-3.60 (1H, m, H-1),2.23-2.41(2H, m), 1.24- 2.05(17H, m), 1.43(3H, s, H-14), 0.84- 1.11(1H,m), 0.96(3H, d, J=6.15 Hz, H- 15), 0.85(3H, d, J=7.17 Hz, H-16); 103.91,91.44, 85.08, 80.77, 54.33, 51.84, 46.01, 37.38, 36.40, 34.23, 34.20,33.11, 32.70, 26.17, 24.74, 23.63, 21.89, 20.31, 14.30; m/z(CI, CH₄)352(M⁺+1, 14), 334(10), 306(100), 288(14), 251 (4), 221(4), 125(10);Anal. Calc. for C₂₀H₃₃NO₄: C, 68.34, H, 9.46; H, 3.98; Found: C, 67.89;H, 9.46; H, 3.92 35 —NR¹N² —H cyclohexyl White solid. δ_(H)5.28(1H, s,H-12), 4.17 (α-isomer) (1H, d, J=9.69 Hz, H-10), 2.93-3.00(1H, mH-1′),2.16-2.41(2H, m), 0.84-2.03 (19H, m), 1.42(3H, s, H-14), 0.95(3H, d,J=6.11 Hz, H-15), 0.85(3H, d, J=7.18 Hz, H-16); δ_(C) 103.87, 91.36,83.36, 80.70, 51.84, 50.94, 46.04, 37.36, 36.38, 34.58, 34.21, 33.18,32.79, 26.29, 26.12, 24.75, 24.71, 24.27, 21.88, 20.29, 14.29, 14.39;m/z(CI, CH₃) 366(M³⁰ +1, 10), 348 (10), 329(100), 318(12), 221(4), 139(8); Anal. Calcd. for C₂₁H₃₅NO₄; C, 69.01; H, 9.65; H, 3.83; found: C,68.85, H, 9.85; H, 3.80. 36

— — Brownish yellow solid. M.p. 112-114° C.; [α]_(D) ²⁰ +12.95°(c.0.0149 in CHCl₃);ν_(max (Neat): 2934, 2872, 2792, 1454, 1376, 1286, 1226, 1192, 1162, 1132, 1102, 1054, 10H, 984, 926, 880, 830 cm)^(−1;) ¹H nmr(300 MHz, CDCl₃) δ_(H) 5.26(1H, s, H-12), 4.02 (1H, d,J=10.20 Hz, H-10, 3.03(2H, m, H-6′a, H-6′b), 2.70(2H, m, H-2′a, H-2′b),2.59(1H, m, H-9), 2.30-2.50(5H, # m, H-8, H-3′a, H-3′b, H-5′a, H-5′b),2.28 (3H, s, N-Me), 1.18-2.05(10H, m, H-2a, H-2b, H-3a, H-3b, H-4, H-5,H-6a, H-6b, H-7a, H-7b), 1.36(3H, s, 1-CH₃), 0.94 (3H, d, J=6.12 Hz,9-CH₃), 0.80(3H, d, J=7.17 Hz, 5-CH₃) ppm; δ_(C) 104.46, 92.16, 90.96,90.98, 56.18, 52.36, 46.82, 38.05, 36.96, 34.97, 29.16, 26.55, 25.46,22.30, 20.96, 14.03; m/z(CI, CH₄) 367([M+1]⁺, 100), 321([M-3CH₃]⁺ # 26).m/z(CI, CH₄) 367 [M+1]⁺, 100), 321([M-3CH₃]⁺, 26). 37 4-vinylphenyl — —White solid. [α]_(D) ²² −64.6°(c 0.028/CHCl₃) (10β-isomer) ν_(max)(film)2948, 2876, 1630, 1512, 1452, 1406, 1376, 1200, 1116, 1074, 1010, 944,904, 882, 844, 788, 756; δ_(H): 7.37(2H, d, J=8.26 Hz, Ar-H), 7.27(2H,d, J=8.26 Hz, Ar-H), 6.71(1H, dd, J=17.62, 10.90 Hz, vinyl-H),5.69-5.76(2H, m, vinyl-H, H- 10), 5.57(1H, s, H-12), 5.20(1H, d, J=10.90Hz, vinyl-H), 2.71-2.78(1H, m) 2.28-2.38(1H, m), 1.17-2.09(9H, m), 1.38(3H, s, H-14), 0.83-0.99(1H, m), 0.98 (3H, d, J=5.74 Hz, H-15), 0.54(3H,d, J=7.67 Hz, H-16); δ_(C) 140.91, 136.75, 135.74, 126.36, 125.72,113.09, 102.40, 90.89, 81.24, 73.07, 81.58, 43.58, 37.58, 36.73, 34.26,32.19, 28.80, 24.98, 24.80, 19.97, 13.75. Anal. Calcd. for C₂₃H₃₀O₄: C,74.56; H, 8.16; found: C, 74.58; H, 8.26. 38 4-Br phenyl — — Whiterectangular crystal. M.p. 156-159° C.; (10β-isomer) [α]_(D) ^(20.5)−45.14°(c 0.0216 in CHCl₃) ; ν_(max) (Nujol): 2924, 1492, 1454, 1374,1112, 1008, 942, 902, 882, 840, 780 cm⁻¹; ¹H nmr (300 MHz, CDCl₃) δ_(H)7.43(2H, d, J=8.40 Hz, H-3, H-5′), 7.19(2H, d, J=8.40 Hz, H-2′, H-6),5.70(1H, d, J=6.60 Hz, H- 10), 5.55(1H, s, H-12), 2.72(1H, m, H- 9),2.33(1H, m, H-8), 1.19-2.10(10H, m, H-2a, H-2b, H-3a, H-3b, H-4, H-5,H-6a, H- 6b, H-7a, H-7b), 1.40(3M, a, 1-CH₃), 0.98 (3H, d, J=5.70 Hz,9-CH₃), 0.48(3M, d, J= 7.80 Hz, 5-CH₃) ppm; m/z(CI, CH₃) 453 ([M(Br⁸¹)+2CH₄]⁺, 18), 451([M(Br⁷⁹)+ 2CH₄]⁺, 20), 425([M(Br⁸¹)+1]⁺, 51).423([M(Br⁷⁹) +1]⁺, 53), 407(40), 405(32), 392(35), 390(48), 379(100),377(88), 335(20), 333(28), 267(32), 221(41) 209(78), 191(78), 191(26),163(59) 39 4-Cl phenyl — — White rectangular crystal. M.p. 161-(10β-isomer) 146° C.; [α]_(D) ^(20.5) −10.35° (c 0.0508 in CHCl₃)ν_(max)(Nujol) 2924, 1494, 1456, 1374, 1114, 1008, 942, 902, 840, 782cm⁻¹; ¹H nmr(300 MHz, CDCl₃) δ_(H) 7.30(2H, d, J=8.16 Hz, H- 3′, H-5′),7.24(2H, d, J=8.16 Hz, H-2′ H-6′), 5.69(1H, d, J=6.60 Hz, H-10), 5.55(1H, m, H-12), 2.71(1H, m, H-9), 2.32(1H, m, H-8), 1.21-2.08(10H, m,H-2a, H-2b, H-3a, H-3b, H-4, H-5, H-6a, H-6b, H-7a, H-7b), 1.36(3M, s,1-CH₃), 0.98(3M, d, J=5.76 Hz, 9-CH₃), 0.49(3H, d, J=7.68 Hz, 5-CH₃)ppm; δ_(C) 140.37, 132.75, 128.66, 128.31, 103.10, 91.64, 81.91, 73.28,52.23, 44.16, 38.28, 37.41, 34.93, 32.80, 26.47, 25.53, 20.63, 14.36;m/z(CI, CH₄) 407([M(Cl³⁷) +2CH₄]⁺, 6), 405([M(Cl³⁵) +2CH₄]⁺, 5),379[M(Cl³⁷) − 1]⁺, 97), 377[M(Cl³⁵) −1]⁺, 100, 355(14), 333(26),182(12). Anal. calc. for C₂₁H₂₃O₄Cl C, 66.57; H, 7.18; found C, 66.42;H, 7.05. 40

— — White solid. δ_(H) 9.00-9.05(1H, m, Ar-H), 8.31-8.41(2H, m, Ar-H),7.05-8.04(2M, m, Ar-H), 7.39-7.57(4H, m, Ar-H), 7.23(1H, d, J=7.51 Hz,H-10), 5.81(1H, s, H-12) 3.10-3.23(1H, m), 0.86-2.49(11H, m), 1.39(3M,s, H-14), 1.09(3M, d, J=5.81 Hz, H-15), 0.57(3M, d, J=7.72 Hz, H-16);134.12, 131.70, 131.05, 130.88, 129.59, 129.19, 128.73, 128.47, 127.61,126.05, 124.55, 124.51, 124.32, 123.71, 102.64, 91.22, 81.42, # 72.62,51.50, 44.18, 37.69, 36.87, 34.33, 33.02, 25.71, 25.09, 25.00, 19.94,13.81. 41

— — White solid. M.p. 89-89.1° C.; [α]_(D) ²⁰: −68.8°(c 0.016 CHCl₃)ν_(max)(film) 2922, 2874, 2362, 1498, 1450, 1376, 1246, 1220, 1110,1040, 1010, 956, 930, 906, 886, 832, 794, 748, 726; δ_(H): 8.68-8.81(2H,m, Ar- H), 7.91-8.10(351, m, Ar-H), 7.57-7.72 (4H, m, Ar-H), 6.50(1H, d,J=6.54 Hz, H-10), 5.75(1H, s, H-12), 3.06-3.19(1H, m), 2.37-2.48(1H, m),2.00-2.16(3H, s), 1.73-1.84 # (2H, m), 0.86-1.60(5H, m), 1.41 (3H, s,51-14), 1.06(3H, d, J=5.67 Hz, H- 15), 0.39(3H, d, J=7.61 Hz, 51-16);135.21, 131.68, 130.H, 129.96, 129.59, 128.84, 125.66, 126.52, 125.04,126.01, 123.84, 123.68, 123.19, 122.33, 102.47, 91.34, 81.42, 69.92,51.45, 43.77, 37.71, 35.89, 34.27, 31.55, 25.79, 25.11, 24.95, 19.96,13.22; m/z(CI, CH₄) 445(M³⁰ +1, 22), 444(100), 398(40), 384(16), 352(16)328(44), 267(6), 218(84), 203(48), 178 # (60), 163(44), 138(70),107(62). 42 2-OCH₃ phenyl — White solid. M.p. 61° C.; [α]_(D) ²⁰ :−14.4°(c (10β-isomer) 0.049 CHCl₃) ; ν_(max)(film) 2928, 2874, 1590,1492, 1462, 1374, 1284, 1240, 1178, 1110, 1102, 1052, 1010, 944, 882,854, 754; δ_(H) 6.83-7.50(4H, m, Ar-H), 5.94(1H, d, J=6.65, Hz, H-10),5.58(1H, s, H-12) 3.84(3H, s, OCH₃), 2.86-2.99(1H, m, H- 9),2.30-2.40(1H, m), 1.19-2.11(10H, m) 1.39(3H, s, H-14), 1.01(151. d,J=5.77 Hz, H-16), 0.43(1H, d, J=7.64 Hz, H-15) δ_(C) 134.85, 127.00,126.37, 120.02, 109.19, 90.86, 68.63, 55.19, 51.30, 43.39, 37.53, 36.72,34.21, 29.87, 25.68, 24.97, 24.75, 19.83, 13.45; m/z(CI, CH₃) 375(M⁺+1,12%), 374(M⁺, 16), 342(100), 329(48) 311(14), 284(28), 182(56), 148(76)137(60), 121(48): Anal. Calcd, forC₂₂H₃₀O_(5: C, 70.56; H, 8.07; found: C,) 70.78; H, 8.28. 432,4-(OCH₃)₂phenyl — — White snow-like crystal. M.p. 62° C.; (10β-isomer)[α]_(D) ²⁰ −64.21°(c. 0.0114 in CHCl₃); (Found C, 68.55; H, 8.14C₂₅H₃₂O₆ requires C, 68.29; H, 7.97%); ν_(max)(Nujol) 2920, 1614, 1590,1506, 1464, 1376, 1286, 1258, 1208, 1156, 1120, 1040, 1010, 946, 880,832, 780, 726 cm⁻¹; ¹H nmr(300 MHz, CDCl₃) δ_(H) 7.33(1H, d, J=8.40 Hz,H-6′), 6.47 (1H, dd, J=8.40, 2.40 Hz, H-5), 6.42(1H, d, J=2.40 Hz,H-3′), 5.84(1H, d, J=6.60 Hz, H-10), 5.54(1H, s, H-12), 3.80, 3.79 (6H,2 ±s, 2 ±OMe), 2.84(1H, m, H-9), 2.32 (1H, m, H-8), 1.20-2.10(10H, m,H-2a, H- 2b, H-3a, H-3b, H-4, H-5, H-6a, H-6b, H- 7a, H-7b), 1.37(3H, s,1-CH₃), 1.00(3H, d, J=5.70 Hz, 9-CH₃), 0.40(3H, d, J=7.50 Hz, 5-CH₃)ppm; m/z(CI, CH₄) 405([M+1]⁺, 15), 359([−3CH₃]⁺, 100), 317(6), 275 (28),221(8), 154(22). Anal. Calc. for C₂₃H₃₂O₆: C, 68.29; H, 7.97%; found C,68.55; H, 8.14; C, 68.47; H, 8.37. 44 2,4,6-(OCH₃)₃ — — Colourless oil.[α]_(D) ²² +10.6°(c 0.016/ phenyl CHCl₃); ν_(max)(film) 2938, 1808,1456, 1204, (10β-isomer) 1154, 1126, 1006, 954; δ_(H): 6.16(1H, d,J=8.09 Hz, 11-10), 6.13(2H, s, Ar-H), 5.52 (1H, s, H-12), 3.81(3H, s,OMe), 3.78 (2±3H, s, OMe), 2.64-2.72(1H, m), 2.29— 2.38(1H, m),1.97-2.08(2H, m), 1.68-1.84 (4H, m), 1.20-1.57(3H, m), 1.40(3H, s,H-14), 0.84-1.11(1H, m), 1.00(3H, d, J=5.73 Hz, H-15), 0.72(3H, d,J=7.70 Hz, H-16); m/z(CI, CH4) 435(M³⁰ +1, 10), 417 (8), 389(100),371(6), 347(10) 329 (16), 221(8) : Anal. Calcd. for C₂₄H₃₄O₃; C, 66.34:H, 7.89; found: C 66.57; H, 8.04. 45 2,4,6-(CH₃)₃ — — Colourless oil.[α]_(D) ²² +13.7(c 0.019/ phenyl CHCl₃); ν_(max)(film) 2938, 2874, 1452,1376, (10β-isomer) 1208, 1106, 1076, 1008, 958, 942, 896, 880, 848, 780,756, 724; 6H: 6.81(2H, s, Ar-H), 6.05(1H, d, J=7.57 Hz, H-10), 5.55 (1H,s, H-12), 2.74-2.85(1H, m), 2.48 (3H, s, Me), 2.26-2.40(1H, m), 2.32(3H,s, Me), 2.27(3H, s, Me), 2.05-2.11(2H, m), 1.64-1.90(4H, m),1.29-1.50(3M, m) 1.41(3H, s, H-14), 0.84-1.04(1H, m), 1.03(3H, d, J=5.91Hz, H-15), 0.64(3M, d, J=7.84 Hz, H-16); δ_(C): 137.22, 135.56, 135.21,133.52, 130.81, 128,37, 102.30, 90.71, 80.94, 71.82, 51.32, 43.92,37.59, 36.79, 34.24, 30.44, 25.72, 25.04, 24.46, 22.28, 20.70, 20.63,19.87, 13.22; m/z (CI, CH₄) 387(M⁺+1, 6), 386(8), 385(10) 341(100),327(8), 299(8), 267(14), 221 (10), 209(4), 163(8), 133(8) Anal. Calcd.C₂₄H₃₄O₄: C, 74.58; H, 8.87; found: C, 74.49; H, 8.86. 46 2,4,5-(CH₃)₃ —— Colourless Oil. M.P. 141° C.; [α]_(D) ²⁰ :55.6° phenyl (C0.068/CHCl₃); ν_(max)(film) 2922, 2874, (10β-isomer) 1502, 1452, 1374,1278, 1220, 1202, 1180, 1120, 1100, 1056, 1040, 1000, 978, 954, 934,896, 880, 820, 754; δ_(H): 7.32(1H, s, Ar-H), 6.99(1H, s, Ar-H),5.94(1H, d, J=6.71 Hz, H-10), 5.67(1H, s, H-12) 2.80-2.90(1H, m),2.38-2.48(1H, m), 2.33 (2±3H, s, Me), 2.31(3H, s, Me), 2.10-2.19 (2H,m), 1.78-2.00(3H, m), 1.40-1.55(4H, m), 1.47(3H, s, H-14), 0.97-1.11(1H,m), 1.11(3H, d, J=5.75 Hz, H-15), 0.55(3H, d, J=7.68 Hz, H-16); δ_(C):136.62, 134.02, 133.13, 131.04, 130.76, 127.09, 102.11, 91.04, 81.07,70.00, 51.33, 43.49, 37.57, 36.73, 34.23, 29.89, 25.57, 25.01, 24.81,19.89, 19.17, 18.73, 13.65; m/z(CI, CH₄) 387(M⁺+1, 10), 386(M⁺, 44),354(60), 341 (84), 296(6), 282(18), 109(20, 182 (28), 160(100), 149(56),133(38), 121 (30); Anal. Calcd. for C₂₄H₃₄O₄: C, 74.58; H, 8.87; found:C, 74.63, H, 8.73. 47 4-COOH phenyl — — White solid. [α]_(D) ²⁰ 63.2°(c0.019/ (10β-isomer) CHCl₃); ν_(max)(film) 2954, 2878, 2670, 2546, 2252,1688, 1612, 1578, 1512, 1452, 1424, 1376, 1314, 1286, 1222, 1208, 1178,1116, 1074, 1056, 1040, 1012, 980, 968, 954, 944, 908, 882, 854, 824,802, 766, 732; δ_(H) 8.09(2H, d, J=8.34 Hz, Ar-H) 7.45(2H, d, J=8.34 Hz,Ar-H), 5.82(1H, d, J=6.63 Hz, H-10), 5.60(1H, s, H-12), 2.76-2.83 (1H,m), 2.31-2.40(1H, m), 1.23-2.10(9H, m), 1.41(3H, s, H-14), 0.87-1.02(1H,m) 1.01(3H, d, J=5.49 Hz, H-15), 0.51(3H, d, J=7.62 Hz, H-16); δ_(C)171.66, 147.41, 129.71, 127.33, 126.15, 102.29, 90.80, 81.07, 72.74,51.35, 43.29, 37.42, 36.53, 34.04, 31.94, 29.05, 25.60, 24.67, 19.78,13.42; m/z(CI, CH₄) 389(M⁺+1,8), 329 (100), 283(36), 267(20), 219(26),177 (80), 129(64). Anal. Calc. for C₂₂H₂₈O₆: C, 68.02; H, 7.27; found:C, 67.77; H, 7.31. 48 4-Phenyl- — — White solid. M.p. 149-150° C.;[α]_(D) ²⁰ + piperazino 16.7⁺(c 1.24 in CHCl₃); ν_(max)(film): 2924,(10β-isomer 1600, 1504, 1450, 1378, 1238, 1206, 1158, 1042, 984, 926,880, 758, 690 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ_(H) (2H, m), 7.03 (2H, d,J=8.0 Hz, H-2″, H-5″), 6.92(1H, t, J=7.3 Hz, H-4), 5.39(1H, a, H-12),4.18(1H, d, J=10.2 Hz), 3.29-3.21(6H, m), 2.90(2H, m), 2.70(1H, m),2.45(1H, m), 2.13(1H, m), 1.95(1H, m), 1.75(2H, m), 1.70-1.20(8H, m),1.20-1.00(4H, m), .93(3H, d, J=7.1 Hz, 6-methyl) ppm; ¹³C NMR(76 MHz,CDCl₃) δ_(C) 151.6, 128.9, 119.3, 116.0, 103.8, 91.6, 90.4, 80.3, 51.7,49.5, 47.2, 45.8, 37.4, 36.3, 34.3, 28.5, 25.9, 24.8, 21.6, 20.3, 13.4ppm; MS (CI, CH₄) m/e 429(M³⁰ +1, 88). Anal. Calcd. forC₂₅H₃₆N₂O_(4: C, 70.06, H,) 8.47, N, 6.53; Found: C, 69.74, H, 8.38, N,6.35. 49 4-(2′- — — White solid. M.p. 158-159° C.; [α]_(D) ²⁰ +methoxyphenyl)- 12.2°(c. 0.752 in CHCl₃); ν_(max)(film): piperazino2936, 1594, 1500, 1448, 1376, 1240, 1180, (10α-isomer) 1118, 1058, 982,926, 880, 828, 750 cm^(−;) ¹H NHR(300 MHz, CDCl₃) δ_(H) 7.10-6.80(4H, m,Ar-H), 5.30(1H, s, H-12), 4.07(1H, d, J=10.2 Hz, H-10), 3.85(3H, s,.—OMe), 3.30-2.95(6H, m), 2.95-2.75(2H, m), 2.61 (1H, m), 2.35(1H, m),2.00(1H, m), 1.85 (1H, m), 1.70(2H, m), 1.60-1.15(9H, m), 1.15-0.90(4H,m), 0.84(3H, 7.2 Hz, 6- methyl) ppm; ¹³C NMR(76 MHz, CDCl₃) δ_(C) 152.3,141.8, 122.5, 120.9, 118.1, 111.2, 103.8, 91.6, 90.4, 80.4, 55.3, 51.8,51.1, 45.9, 37.4, 36.4, 34.3, 28.5, 26.0, 24.8, 21.7, 21.7, 20.3, 13.4ppm; MS(CI, CH₄) m/e 459(M⁺+1, 55) . Anal. Calcd. forC₂₆H₃₈N₂O_(5: C, 68.10, H, 8.35, N, 6.11;) Found: C, 67.74, H, 8.35, N,5.83. 50 4-(4′- — — White solid. M.p. 157-158° C.; [α]_(D) ²⁰ +fluorophenyl)- 23.1°(c 0.743 in CHCl₃); ν_(max)(film) piperazino 2933,2842, 1704, 1689, 1654, 1617, 1560, (10α-isomer 1516, 1456, 1381, 13H,1249, 1227, 1205, 1160, 1135, 11H, 1061, 1047, 1027, 985, 921, 883, 853,822, 697 cm⁻¹; ¹H NMR(300 MHz, CDCl₃) δ_(H) 7.00-6.80(4H, m Ar-H),5.29(1H, s, H-12), 4.07(1H, d, J=10.2 Hz), 3.15-3.05(6H, m), 2.83(2H,m), 2.60 (1H, m), 2.35(1H, m), 2.00(1H, m), 1.90 (1H, m), 1.73(2H, m),1.70-1.10(9H, m) 1.10-0.90(4H, m), 0.83(3H, d, J=7.1 Hz, 6-methyl) ppm;¹³C NMR(76 MHz, CDCl₃) δ_(C) 156.8(d, ¹J_(C-F)=238 Hz), 148.2(d,⁴J_(C-F)= 1.96 Hz), 117.6(d, ³J_(C-F)=7.55 Hz), 115.2(d, ²J_(C-F)=21.9Hz), 103.7, 91.5, 90.3, 80.2, 51.6, 50.4, 47.1, 45.7, 37.3, 36.2, 34.2,28.4, 25.9, 24.7, 21.5, 20.2, 13.3 ppm; MS(CI, CH₄) m/e 447(M⁺+1, 82)Anal. Calcd. for C₂₅H₃₅N₂O₄F: C, 67.24, H, 7.90, N, 6.27; Found: C,67.28, H, 8.01, N, 5.95. 51 4-(2′-pyridyl)- — — White solid. M.p.146-147° C.; [α]_(D) ²⁰ +16.40 piperazino c 1.34 in CHCl₃);ν_(max)(film) 2926, 2872, (10α-isomer) 1596, 1564, 1482, 1346, 1378,1312, 1248, 1208, 1160, 1132, 1056, 1026, 980, 926, 880, 850, 828, 744,732 cm⁻¹; ¹H NMR(300 MHz, CDCl₃) δ_(H) 8.17(1H, dd, J=1.3, 5.0 Hz,14-6′),7.44(1H, td, J=1.8, 3.4 Hz, H-4″), 6.64-6.55(2H, m, H-3″& H-5″),5.27(1H, s, H-12), 4.07(1H, d, J=10.3 Hz, 14-10), 3.52-3.48(4H, m, H-3′&H- 5′), 3.10-3.05(2H, m), 2.79-2.74(2H, m), 2.76(1H, m), 2.32(1H, m),2.02-1.80 (2H, m), 1.70-1.65(2H, m), 1.50-1.20 (8H, m), 1.10-0.90(4H,m), 0.83(3H, d, J=7.2 Hz, 6-methyl) ppm; ¹³C NMR(76 MHz, CDCl₃) δ_(C)153.6, 147.8, 137.2, 112.8, 107.0, 103.8, 91.6, 90.6, 80.3, 51.7, 47.1,45.8, 45.5, 37.3, 36.3, 34.3, 28.5, 25.9, 24.7, 21.6, 20.3, 13.4 ppm;MS(CI, NH₃) m/e 430(M⁺+1, 100); Anal. Calcd. for C₂₄H₃₅N₃O₄: C, 67.H, H,8.21, N, 9.78; Found C, 67.01, H, 8.22, N, 5.55. 52 4-(3′- White solid.M.p. 126-127° C.; [α]_(D) ²⁰ + trifluoromethyl- 23.00(c. 0.543 inCHCl₃); ν_(max)(film): phenyl)- 2928, 2874, 1612, 1588, 1496, 1450,1412, piperazino 1378, 1356, 1320, 1266, 1242, 1208, 1164, (10α-isomer)1122, 1100, 1054, 986, 948, 926, 880, 860, 828, 788, 732, 696, 648 cm⁻¹;¹H NMR (300 MHz, CDCl₃) δ_(H) 7.33(1H, m, H-5″), 7.10-7.02(3H, m, Ar-H),5.30(1H, s, H- 12), 4.09(1H, d, J=10.2 Hz, H-10), 3.40-3.05(6H, m),2.84(2H, m), 2.65 (1H, m), 2.35(1H, m), 2.00(1H, m), 1.85 (1H, m),1.80-1.60(2H, m), 1.60-1.15 (10H, m), 1.15-0.90(4H, m), 0.84(3H, d,J=7.1 Hz) ppm; ¹³C NMR(76 MHz, CDCl₃) δ_(C) 151.7, 129.4, 118.7, 115.4,111.9, 103.9, 91.6, 90.5, 80.3, 51.7, 49.0, 47.0, 45.8, 37.4, 36.3,34.3, 28.5, 25.9, 24.8, 21.6, 20.3, 13.4 ppm; ¹⁹F NMR(282 MHz, CDCl₃)δ_(F) 63.9 ppm; MS(CI, CH₄) m/e 497(M³⁰ +1, 58) Anal. Calcd. forC₂₆H₃₅N₂O₄F₃: C, 62.89, H,7.10, N, 5.64; Found: C, 62.82, H, 7.27, N,5.58. 53 4-Fluorophenyl — — White solid. M.P. 133.6-134.8° C.; [α]_(D)²⁰ − (10β-isomer) 35.66°(c 0.83, CHCl₃); δ_(F): −118.00; IR (neat)ν_(max) 2952, 2873, 1604, 1510, 1452, 1376, 1222, 1110, 1040, 1010, 944,906, 882, 838, 782; δ_(H): 7.29-7.24(2H, m, Ph), 7.04-6.97(2H, no, Ph),5.70(1H, d, H-10, J=6.70 Hz), 5.55(1H, s, H-12) 2.77-2.65(1H, m),2.39-2.28(1H, m) 2.10-1.97(2H, m), 1.90-1.82(1H, m), 1.78-1.64(2H, m),1.49-1.17(8H, m), 0.99(3H, d, 6-Me, J=5.75 Hz), 0.48(3H, d, 9-Me, J=7.68Hz) δ_(C) 162.10(d, Ph, J_(CF)=244.0 Hz), 137.42(d, Ph, J_(CF)=3.09 Hz),128.30(d, Ph, J=7.84 Hz), 115.16 (d, Ph, J_(CF)=21.27 Hz), 102.92,91.55, 81.75, 73.15, 52.09, 44.05, 38.H, 37.30, 34.82, 32.78, 26.35,25.57, 25.42, 20.52, 14.29; MS(CI positive, NH₃) m/z: 382 (MNH₄ ⁺,2±¹³C, 4%), 381(MNH₄ ⁺, 2±¹³C, 25%) 380(MNH₄ ⁺, base peak), 363(MH, 6%);Anal. Calcd. for C₂₃H₂₇O₄F C 69.59, H 7.51; found C 69.51, H 7.62. 541-(2-pyrimidyl)- — — White solid. M.p.147.1-147.5° C.; [α]_(D) ²⁰ :piperazino +14.3°(c=0.86,CHCl₃) ; IR(KBr) ν_(max) isomer) 2988, 2970,2948, 2918, 2870, 2854, 1588, 1546, 1502, 1452, 1438, 1430, 1396, 1376,1308, 1268, 1186, 1160, 1132, 11H, 1102, 1060, 1044, 1022, 980, 940,926, 880, 852, 826, 798, 742, 694, 640; δ_(H) : 8.27 (2H, d, o-Ph, J=4.8Hz) 6.43(1H, t, p- Ph, J=4.8 Hz), 5.27(1H, s, H-12), 4.05 (1H, d, H-10,J=10.2 Hz), 3.87-3.72(4H, m, 2±NCH₂), 3.08-3.01(2H, m), 2.75-2.59 (4H,2±NCH₂), 2.38-2.27(1H, m), 2.02- 1.37(8H, m), 1.34(3H, s, 3-Me), 1.33-1.17(1H, m), 0.94(3H, d, 6-Me, J=6.1 Hz), 0.85(3H, d, 9-Me, J=7.16 Hz);δ_(C): 162.39, 158.31, 110.17, 104.56, 92.34, 91.49, 80.99, 52.44,47.95, 46.56, 44.76, 38.07, 37.02, 34.99, 29.20, 26.66, 25.44, 22.34,20.97, 14.22; MS(CI, CH₄) m/z: 432(MH⁺, ¹³C, 5%), 431(MH, 33%) ; Anal.calcd. for C₂₃H₃₄N₄O₄: C 64.16, H 7.96, N 13.01; found C 64.09, H 8.07,N 12.86. 55 1-(4- — — White solid. M.p. 140.7-142.8° C.; [α]_(D) ²⁰ :Chlorophenyl)- +9.41(c=1.01, CHCl₃); IR(KBr) ν_(max): piperazino 2976,2952, 2934, 2894, 2872, 2842, 1596, 10β-isomer 1502, 1454, 1378, 1350,1316, 1286, 1248, 1206, 1184, 1160, 1136, 1108, 1060, 1046, 1026, 956,982, 882, 852, 816, 698, 666, 518; δ_(H): 7.20(2H, d, Ph, J=9.0 Hz),6.85)2H, d, Ph, J=9.02 Hz), 5.30(1H, s, H-12), 4.09(1H, d, H-10, J=10.23Hz), 3.20-3.07(8H, m, 4±NCH₂), 2.86-1.20 (15H, m), 0.96(3H, d, 6-Me,J=6.09 Hz), 0.84(3H, d, 9-Me, J=7.18 Hz); δ_(C): 150.93, 129.49, 124.75,117.83, 104.57, 92.29, 91.11, 81.02, 52.39, 50.18, 47.74, 46.H, 38.08,36.99, 34.97, 29.21, 26.65, 25.45, 22.33, 20.97, 14.14; MS(CI positive,CH₄) m/z: 465(MH⁺, ³⁷Cl, 2%), 464(MH⁺, ¹³C, 0.4%), 463(MH, 6%); Anal.Calcd. for C₂₅H₃₅N₂O₄Cl: C 64.85, H 7.62, N 6.05; found: C 64.68, H7.66, N 5.89. 56 1-(3- — — White solid. M.p. 137.3-137.8° C.; [α]_(D) ²⁰: Chlorophenyl- +12.13°(c=0.89, CHCl₃) IR(KBr) ν_(max) piperazino 2976,2948, 2922, 2876, 2864, 2848, 2826, 10α-isomer 1598, 1566, 1486, 1452,1430, 1412, 1378, 1360, 1328, 1312, 1284, 1274, 1264, 1244, 1206, 1184,1158, 1136, 1116, 1102, 1086, 1042, 1028, 988, 942, 928, 880, 854, 832,782, 774, 680; δ_(H): 7.18-7.12(1H, m, Ph), 6.88-6.77(3H, m, Ph),5.30(1H, s, H- 12), 4.08(1H, d, H-10, J=10.21 Hz), 3.24-3.12(6H, m,3±NCH₂), 2.84-2.78 (2H, m, NCH₂), 2.66-2.59(1H, m), 2.41— 2.30(1H, m),2.05-1.20(13H, m), 0.96 (3H, d, 6-Me, J=6.06 Hz), 0.84(3H, d, 9- Me,J=7.17 Hz); δ_(C): 153.36, 135.54, 130.59, 119.58, 116.33, 114.58,104.63, 92.34, 91.18, 81.05, 52.44, 49.75, 47.76, 46.55, 38.11, 37.02,35.00, 29.25, 26.67, 25.48, 22.37, 20.99, 14.16; MS (ES) m/z: 465(MH⁺,¹³C, 10%), 464(MH⁺, ¹³C, 9%) 463(MH⁺, 100%); Anal. Calcd forC₂₅H₃₅N₂O₄Cl: C 64.85, H 7.62, N 6.05, found: C 64.91, 7.73, N 6.00. 571-(2- — — White solid. M.p. 72-75° C., [α]_(D) ²⁰ −5.15° Chlorophenyl)-(c 1.01, CHCl₃); IR(neat) ν_(max) 3062, 2926, piperazino 2870, 2360,1588, 1480, 1450, 1376, 1232, 1206, 1124, 1040, 984, 926, 880, 828, 762,668; δ_(H): 7.37-6.92(4H, m, Ph), 5.32(1H, s, H-12), 4.09(1H, d, H-10,J=10.21 Hz), 3.23-3.05(8H, m, 4±NCH₂), 2.67-2.60(1H, m, H-9), 2.41(11H,m), 2.37-1.20(13H, m), 0.96(3H, d, 6-Me, J=6.14 Hz), 0.85(3H, d, 9-Me,J=7.19 Hz); δ_(C): 150.37, 131.31, 129.50, 128.11, 124.00, 120.99,104.62, 92.40, 91.29, 81.07, 52.49, 52.38, 46.61, 38.09, 37.07, 35.02,29.26, 26.72, 25.47, 22.39, 21.00, 14.21; MS(ES positive) m/z: 465(MH⁺,³⁷Cl, 20%), 464(MH⁺, ¹³C, 19%), 463(MH⁺, 100%); Anal. Calcd forC₂₅H₃₅N₂O_(4Cl: C) 64.85, H 7.62, N 6.05; found: C 64.92, H 7.67, N5.77. 58 1-(4- — — White solid. M.p. 147.6-148.4° C.; [α]_(D) ²⁰ :Methoxyphenyl)- +9.07°(c 1.08, CHCl₃); IR(KBr) ν_(max) 2958, piperazino2924, 2846, 2810, 1512, 1484, 1448, 1420, 1378, 1350, 1326, 1310, 1292,1264, 1248, 1206, 1182, 1160, 1134, 1108, 1086, 1060, 1038, 1026, 1010,984, 942, 926, 880, 852, 824, 814, 800; δ_(H): 6.93-8.81(4H, m, Ph),5.30(1H, s, H-12), 4.08(1H, d, H-10, J=10.20 Hz), 3.77(3H, s, OMe)3.20-3.04(6H, m, 3±NCH₂), 2.86-2.80 (2H, m, NCH₂), 2.66-2.59(1H, m),2.41— 2.31(1H, m), 2.05-1.21(13H, m), 0.96 (3H, d, 6-Me, J=6.08 Hz),0.84(3H, d, 9- Me, J=7.16 Hz); δ_(C): 154.22, 146.81, 118.81, 115.00,104.53, 92.27, 91.06, 81.03, 56.22, 52.40, 51.70, 47.93, 46.54, 38.07,37.00, 34.98, 29.22, 26.64, 25.46, 22.34, 20.98, 14.12; MS(ES positive)m/z: 459(MH⁺, 100%), 458(H, 58%) Anal. Calcd. for C₂₆H₃₈N₂O₅: C 68.10, H8.35, N 6.11; found: C 68.16, H 8.42, N 5.97. 59 1-(ortho-Tolyl)- — —White solid, m.p. 141.6-142.8° C.; [α]_(D) ²⁰ piperazino +12.55°(c 1.02,CHCl₃) ; IR(neat) ν_(max) 10α-isomer 3026, 3021, 2926, 2872, 2360, 1598,1492, 1448, 1376, 1328, 1306, 1258, 1226, 1206, 1180, 1156, 1132, 1118,1056, 1040, 1026, 982, 958, 926, 880, 850, 828, 762, 722, 668; δ_(H):7.19-7.14(2H, s, Ph), 7.07-6.94 (2H, s, Ph), 5.33(1H, s, H-12), 4.10(1H, d, H-10, J=10.17 Hz),3.19-3.14(2H, m, NCH₂), 2.97-2.79(6H, s,3±NCH₂), 2.71-2.59(1H, m, H-9), 2.37(1H, m), 2.32(3H, s, PhMe),2.07-2.00(1H, m), 1.71-1.17(11H, s), 0.97(3H, d, 6-Me, J=6.1 Hz),0.87(3H, d, 9-Me, J=7.2 Hz); δ_(C): 174.96, 152.60, 133.43, 131.66,127.07, 123.47, 119.54, 104.61, 92.45, 91.35, 81.08, 52.84, 52.48,46.59, 38.07, 37.05, 35.00, 29.25, 26.75, 25.55, 22.38, 20.99, 18.64,14.22; MS(CI CH₄) m/z: 444 (MH⁺, ¹³C, 5.1%), 443(MH⁺, 18%), 442(M⁺,7.6%); Anal. Calcd for C₂₆H₃₈N₂O₄: C 70.56, H 8.65, N 6.33; found C70.43, H 8.54, N 6.28. 60 4- — — White solid, M.p. 137.6-138.9° C.;[α]_(D) ²⁰ Benzylpiperidino +10.82°(c 0.98, CHCl₃) ; IR(neat) ν_(max)10α-isomer 2924, 2870, 1452, 1376, 1206, 1132, 1098, 1056, 970, 925,880, 746, 700; δ_(H): 7.28-7.24(2H, m, Ph), 7.19-7.12(3H, m, Ph),5.25(1H, s, H-12), 4.00(1H, d, H- 10, J=10.16 Hz), 3.00-2.86(2H, m),2.69- 2.27(6H, m), 2.02-1.41(10H, m), 1.38 (3H, s, 3-Me), 1.33-1.12(4H,m), 1.09- 0.97(1H, m), 0.93(3H, d, 6-Me, J=6.12 Hz), 0.78(3H, d, 9-Me,J=7.18 Hz); δ_(C): 141.60(Ph), 129.75(Ph), 128.73(Ph), 126.28(Ph),104.44, 92.40, 91.75, 81.06, 52.46, 46.64, 44.16, 44.03, 38.85, 38.02,37.02, 34.99, 33.49, 33.18, 29.36, 26.72, 25.41, 22.32, 20.97, 14.20;MS(CI positive, NH₃) m/z: 444(MH⁺, 2±¹³C, 2%), 443(MH⁺, ¹³C, 12%),442(MH⁺, 38%), 441(M⁺, 1%); Anal Calcd. For C₂₇H₃₉NO₄: C 73.44, H 8.90,N 3.17; found C 73.25, H 8.85, N 3.14. 61 6- — — δ_(H): 7.73-7.70(3H, m,Ph), 7.59-7.55(1H, Methoxynaphtyl m, Ph), 7.13-7.10(2H, m, Ph), 4.50(1H,10α- and 10β- d, H-10, J=10.64 Hz), 3.91(3H, s, Ome), isomers2.72-2.65(1H, m), 2.49-2.43(1H, m), 2.10-2.02(1H, m), 1.96-1.87(1H, m),1.81-1.74(1H, m), 1.68-1.53(4H, m), 1.46 (3H, s, 3-Me), 1.42-1.24(3H,m), 1.13- 1.05(1H, m), 0.99(3H, d, 6-Me, J=6.15 Hz), 0.55(3H, d, 9-Me,J=7.19 Hz); δ_(C): 158.18, 136.70, 135.07, 130.13, 129.28, 127.65,127.01, 126.46, 119.24, 106.32, 104.92, 92.76, 81.36, 79.15, 55.93,52.70, 46.78, 38.12, 37.05, 34.93, 34.55, 26.75, 25.51, 22.20, 21.01,14.80, MS(ES positive) m/z: 424(MH⁺, 4%), δ_(H): 7.74- 7.67(3H, m, Ph),7.39-7.35(1H, m, Ph), 7.14-7.11(2H, m, Ph), 5.86(1H, d, H-10, J=3.72Hz), 5.54(1H, s, H-12), 3.91(3H, s, OMe), 2.86-2.78(1H, m), 2.40-2.30(1H, m), 2.09-1.58(5H, m), 1.51-1.23 (7H, m), 0.99(3H, d, 6-Me, J=5.58Hz), 0.94-0.88(1H, m), 0.52(3H, d, 9-Me, J=7.65 Hz); δ_(C): 157.97,137.12, 134.08, 130.11, 129.39, 126.83, 126.19, 124.98, 119.23, 106.29,103.09, 91.72, 81.99, 73.86, 55.94, 52.29, 44.28, 38.29, 37.45, 34.97,32.96, 26.51, 25.70, 25.57, 20.67, 14.52; MS(CI positive, CH₄) m/z:426(MH⁺, ¹³C, 2%), 425(MH⁺, 8%), 424(M⁺, 7%).

EXAMPLE 62

The parasiticidal activity of compounds of the invention wasinvestigated by means of the following tests.

Abbreviations used in the examples:

-   CO₂=carbon dioxide-   DMSO=dimethylsulphoxide-   ED=dermal cell line of a horse-   EDTA=ethylenediaminetetraacetic acid-   FCS=fetal calf serum-   RPMI=growth medium for cell cultures-   rmp=revolutions per minute-   VERO=kidney cell line of the African green monkey    (a) Screening of Compounds Against Neospora Caninum Cell Cultures In    Vitro.

Screening was conducted in 96-well plates (Falcon 3872). A monolayer ofhost cells (VERO or ED) were placed on a cell culture plate.Non-infected mono-layers of cells were cultured in two 50 ml tissueculture bottles (50 cm³ cell culture area). The cell layer was detachedwith trypsin-EDTA (5 ml. Gibco 45300-019) in a CO₂-culture cupboard at37° C. After 10 minutes, most of the cells were detached. The cells weretransferred with a 5 ml pipette into a 50 ml centrifuge tube (Greiner,B769331) containing about 1 ml warmed fetal calf serum. Aftercentrifugation for 5 minutes at 1500 rpm (Varifuge 3.0, Heraeus), theliquid was removed and the cell pellet suspended in RPMI medium (100 ml,95% RPMI 1640, 2% FCS, 1% L-glutamine, 1% sodium hydrogen carbonate, 1%penicillin/streptomycin). The cell suspension was pipetted into six96-well plates at 150 μl per well. The coated cell culture plates wereplaced in an incubation cupboard at 37° C. under 5% CO₂ for 24 hours.The cells were then infected with Neospora caninum tachyzoites at aconcentration of 48,000 tachyzoites per well. This was followed byincubation at 37° C. under 5% CO₂ for 24 hours.

The test compounds (0.5-1.5 mg) were weighed into 1.5 ml eppendorfvessels and dissolved in 1 ml dimethyl sulphoxide, corresponding to adilution of about 1×10⁻³ g ml⁻¹. The medium used for further dilutionconsisted of 87% RPMI 1640, 10% FCS, 1% L-glutamine, 1% sodium hydrogencarbonate, 1% penicillin/streptomycin. In the first screening,concentrations of 10⁻⁵, 10⁻⁶ and 10⁻⁷ g ml⁻¹ were used. The dilutedpreparations were then transferred to the cell culture plates at avolume of 150 μl per well after 24 hour infection with Neospora caninum.For the first row, untreated medium was used; this row containedinfected and uninfected cells as controls, The cell plate was incubatedat 37° C. under 5% CO₂ for 5 days. Microscopic evaluation was conducted4 days after treatment and 5 days after infection at a magnification of25×10 in an inverse microscope according to the following evaluationscheme. Evaluation Observable effect 0 = no effect monolayer completlydestroyed 1 = weak effect monolayer partly destroyed, parasite clumpscan be seen 2 = full effect monolayer intact, no tachyzoites observableT = cytotoxic cells are dead, lysed

The results are set out in Table II below: TABLE II Example Dose (g/ml)No. 10⁻⁵ 10⁻⁶ 10⁻⁷ 10⁻⁸  2 1 1 0 — 15 T/1 1 1 0 18 2 1 0 — 19 T 0 — — 20T/1 1 1 0 21 2 0 — — 23 T/2 0 — — 24 1 0 — — 25 T/1 1 1 0 30 1 0 — — 312 1 0 — 32 2 0 — — Artemisinin 0 — — —(b) Screening of Compounds Again Eimeria Tenella Cell Cultures In Vitro

Cells from kidneys of 19 day old chicks are cultured as monolayers in96-well plates (Falcon 3872) in a medium of Hanks lactalbuminehydrolysate, 5% fetal calf serum, 1% glutamine and 1% non-essentialamino acids. After two days at 42° C. under 5% CO₂, the culture wasinfected with excised sporozoites of Eimeria tenella at about 30.00 perwell. Test compounds were dissolved in DMSO and diluted with culturemedium to a maximum end concentration of 10 μg ml⁻¹. The dilution stepswere 1:10. On day 5 post infection, the cultures were evaluated under amicroscope at 100-fold magnification and the condition of the host cellsand the amount of intact schizonts and free merozoites was determined.Effectiveness was rated as follows: Evaluation Observable effect 3 =very active no intact parasites/well 2 = active 1-6 parasites per well 1= weakly active up to 1 intact schizont/optical field of vision 0 =inactive >1 intact schizont/optical field of vision T = cytotoxic hostcells are dead

The results are set out in Table III below: TABLE III Dose (g/ml)Example No. 10⁻⁵ 10⁻⁶ 10⁻⁷ 10⁻⁸  2 2 2 1 0 15 2 2 1 0 18 T T 1 0 19 T T1 0 20 T T/2 0 — 21 T/2 0 — — 23 T T/2 0 — 24 2 1 0 — 25 2 1 1 0 30 T 20 — 31 T 1 0 — 32 T 2 0 — Artemisinin 2 1 0 —(c) In Vitro Screening Against Plasmodium Falciparum

Two parasite strains—W2 resistant to chloroquine, and D6 sensitive tochloroquine but resistant to mefloquine were used. In Table IV below,the best compounds should show no cross resistance between the twostrains.

The assay relies on incorporation of radiolabelled hypoxanthine by theparasite and inhibition of incorporation is attributed to activity ofknown or candidate antimalarial drugs. For each assay, provenantimalarials such as chloroquine, mefloquine, quinine, artemisinin andpyrimethamine were used as controls. The incubation period was 66 hours,and the starting parasitemia was 0.2% with 1% hematocrit. The medium wasan RPMI-1640 culture with no folate or p-aminobenzoic acid. Albumaxrather than 10% normal heat inactivated human plasma was used as, withAlbumax, less protein binding is observed, and compounds elicit slightlyhigher activities in this model. If a compound was submitted with noprior knowledge of activity, it was dissolved directly in dimethylsulphoxide (DMSO), and diluted 400 fold with complete culture medium.The unknown compound was started at a maximum concentration of 50,000 ngml⁻¹ and sequentially diluted 2-fold for 11 times to give aconcentration range of 1048 fold. These dilutions were performedautomatically by a Biomek 1000 Liquid Handling System in 96-wellmicrotiter plates. The diluted drugs were then transferred to testplates, 200 μl of parasitized erythrocytes were added, and incubated at37° C. in a controlled environment of 5% CO₂, 5% O₂ and 90% N₂. After 42hours, 25 μl of ³H-hypoxanthine was added, and the plates incubated foran additional 24 hours. After 66 hours, the plates were frozen at −70°C. to lyse the red cells, and then thawed and harvested onto glass fiberfilter mats in a 96-well harvester. The filter mats were then counted ina scintillation counter. For each drug, the concentration responseprofile was determined and 50%, 90% and 10% inhibitory concentrations(IC₅₀, IC₉₀, and IC₁₀) were determined by a non-linear logistic doseresponse analysis program.

A prescreen format can be used wherein a 3-dilution assay may be used todetermine activity at high medium or low concentrations. Theconcentrations were selected as 50,000, 500 and 50 ng ml⁻¹. These wereperformed in duplicate on a 96-well format plate with 14 test compoundsand one known (standard) compound per plate. The system was automatedwith a Biomek diluter for mixing and diluting the drugs, and addingdrugs and parasites to a test plate. In the prescreen format, if theANALYSIS FIELD (AF) has a “<”, then the compound was “very active” andthe IC values are most likely to be below the last dilution value (innanograms/ml), which is listed next to AF. In most cases, thesecompounds were run again at lower starting concentration to determinethe true IC value. If the AF has a “>”, then the IC value is greaterthan the prescreen dilution value; thus “AF>250” means that the IC valueis greater than 250 ng ml⁻¹ and no further screening is carried out. Insuch cases, values of 0.00 are entered for IC values.

The results are set out in Table IV below: TABLE IV In vitro activty:IC₅₀; IC₉₀; (IC₁₀)ng/ml W2 Strain D6 Strain Example No. (Chloroquineresistant) (Chloroquine sensitive) IA(10α-isomer) 0.69; 0.97 0.64; 1.24IB(10β-isomer) 0.69; 0.98 0.74; 1.36  2 0.31; 0.52; (0.19) 0.73; 0.99;(0.53)  4 0.84; 1.74; (0.40) 1.05; 2.10; (0.52) 12 0.78; 1.32, (0.47)0.77; 1.70; (0.35) 15 0.66; 0.84; (0.52) 0.61; 0.78; (0.48) 16 0.64;0.84; (0.49) 0.61; 0.78; (0.48) 18 0.23; 0.33; (0.17) 0.28; 0.82; (0.09)19 0.33; 0.43; (0.25) 0.39; 0.80; (0.19) 20 5.81; 12.77; (2.64) 9.40;12.93; (6.84) 21 0.00; 0.00 250AF < 0 1.77; 3.96; (0.79) 23 0.00; 0.00;AF > 250 0.00; 0.00; AF > 250 24 0.77; 1.30; (0.46) 1.17; 2.10; (0.65)25 0.11; 0.17; (0.07) 0.09; 0.35; (0.02) 26 0.00; 0.00 AF < 4 9.05;16.24; (5.05) 30 0.00; 0.00; 250AF < 0 11.20; 18.61; (6.74) 31 0.29;0.68; (0.12) 1.35; 2.42; (0.75) 32 0.45; 0.92; (0.22) 2.45; 3.97; (1.51)36 0.26; 0.61; (0.11) 0.38; 0.77; (0.19) 38 1.23; 2.76 (0.55) 0.90;3.69; (0.22) 41 0.73; 1.7; (0.30) 1.53; 2.04; (1.16) 44 0.3318; 0.8168;(0.13) 0.69; 1.67; (0.29)

1. A method of treating or preventing a disease caused by infection witha parasite other than an organism of the genus Plasmodium, comprisingadministering to a host in need thereof an effective amount of acompound of the general formula I

or a salt thereof, in which Y represents a halogen atom, an optionallysubstituted cycloalkyl, aryl, C-linked heteroaryl or heterocyclylalkylgroup or a group —NR¹R²; where R¹ represents a hydrogen atom or anoptionally substituted alkyl, alkenyl or alkynyl group; R² represents anoptionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, aryl oraralkyl group; or R¹ and R² together with the interjacent nitrogen atomrepresent an optionally substituted heterocyclic group or an amino groupderived from an optionally substituted amino acid ester.
 2. The methodof claim 1 in which Y represents a halogen atom.
 3. The method of claim2 in which Y represents a fluorine or bromine atom.
 4. The method ofclaim 1 in which Y represents a C₃₋₈ cycloalkyl group, a C₆₋₁₈ arylgroup, a 5- to 10-membered C-linked heteroaryl group or a 5- to10-membered heterocyclyl-C₁₋₆ alkyl group, each group being optionallysubstituted by one or more substituents selected from the groupconsisting of halogen atoms, hydroxyl, C₁₋₄ alkyl, C₂₋₄ alkenyl, C₁₋₄haloalkyl, C₁₋₄ alkoxy, amino, C₁₋₄ alkylamino, di(C₁₋₄ alkyl)amino,carboxyl, C₆₋₁₀ aryl, 5 to 10-membered heterocyclic and C₁₋₄ alkyl- orphenyl-substituted 5- to 10-membered heterocyclic groups.
 5. The methodof claim 4 in which Y represents a C₆₋₁₈ aryl group optionallysubstituted by one or more substituents selected from the groupconsisting of halogen atoms, hydroxyl, C₁₋₄ alkyl, C₂₋₄ alkenyl, C₁₋₄haloalkyl, C₁₋₄ alkoxy, C₁₋₄ haloalkoxy, amino, C₁₋₄ alkylamino, di(C₁₋₄alkyl)amino and carboxyl groups.
 6. The method of claim 4 in which Yrepresents a phenyl, naphthyl, anthryl or phenanthryl group, each groupbeing optionally substituted by one or more substituents selected fromthe group consisting of halogen atoms and hydroxyl, methyl, vinyl, C₁₋₄alkoxy and carboxyl groups.
 7. The method of claim 4 in which Yrepresents a phenyl, fluorophenyl chlorophenyl, bromophenyl,trimethylphenyl, vinylphenyl, methoxyphenyl, dimethoxyphenyl,trimethoxyphenyl, carboxylphenyl, naphthyl, hydroxynaphthyl,methoxynaphthyl, anthryl or phenanthryl group.
 8. The method of claim 7in which Y represents a phenyl or trimethoxyphenyl group.
 9. The methodof claim 1 in which Y represents a group —NR¹R² where R¹ represents ahydrogen atom or a C₁₋₆ alkyl group and R² represents a C₁₋₆ alkyl, C₃₋₈cycloalkyl, C₆₋₁₀ aryl or C₇₋₁₆ aralkyl group, or R¹ and R² togetherwith the interjacent nitrogen atom represent a 5- to 10-memberedheterocyclic group or an amino group derived from a C₁₋₆ alkyl ester ofan amino acid, each group being optionally substituted by one or moresubstituents selected from the group consisting of halogen atoms, C₁₋₄alkyl, C₁₋₄ haloalkyl, C₁₋₆ alkoxycarbonyl, phenyl, halophenyl, C₁₋₄alkylphenyl, C₁₋₄ haloalkylphenyl, C₁₋₄ alkoxyphenyl, benzyl, pyridyland pyrimidinyl groups.
 10. The method of claim 9 in which Y representsa group —NR¹R² where R¹ represents a hydrogen atom or a C₁₋₄ alkyl groupand R² represents a C₁₋₄ alkyl, C₃₋₆ cycloalkyl, phenyl or benzyl group,or R¹ and R² together with the interjacent nitrogen atom represent a 6-to 10-membered heterocyclic group or an amino group derived from a C₁₋₄alkyl ester of an amino acid, each group being optionally substituted byone or more substituents selected from the group consisting of halogenatoms, C₁₋₄ haloalkyl, C₁₋₄ alkoxycarbonyl, phenyl, halophenyl, C₁₋₄alkylphenyl, C₁₋₄ haloalkylphenyl, C₁₋₄ alkoxyphenyl, benzyl, pyridyland pyrimidinyl groups.
 11. The method of claim 9 in which Y representsa propylamino, cyclopentylamino, cyclohexylamino, phenylamino,fluorophenylamino, chlorophenylamino, bromophenylamino, iodophenylamino,methoxycarbonylphenylamino, biphenylamino, benzylamino,fluorobenzylamino, bis(trifluoromethyl)benzylamino, phenylethylamino,phenyl-methoxycarbonylmethylamino, diethylamino, morpholinyl,thiomorpholinyl, morpholinosulphonyl, indolinyl,tetrahydroisoquinolinyl, phenylpiperazinyl, fluorophenylpiperazinyl,chlorophenylpiperazinyl, methylphenylpiperazinyl,trifluoromethylphenylpiperazinyl, methoxyphenylpiperazinyl,benzylpiperazinyl, pyridylpiperazinyl and pyrimidinylpiperazinyl group.12. The method of claim 9 in which Y represents a propylamino,phenylamino, bromophenylamino, iodophenylamino, biphenylamino,benzylamino, bis(trifluoromethyl)benzylamino, phenylethylamino,phenyl-methoxycarbonylmethylamino or morpholinyl group.
 13. The methodof claim 1 in which the parasite is an organism of the genus Neospora orthe genus Eimeria. 14-26. (canceled)
 27. A method for treating orpreventing a disease caused by infection with a parasite of the genusPlasmodium which comprises administering to a host in need of suchtreatment a therapeutically effective amount of a compound of generalformula I

or a salt thereof, in which Y represents a halogen atom, an optionallysubstituted cycloalkyl, aryl, C-linked heteroaryl or heterocyclylalkylgroup or a group —NR¹R²; where R¹ represents a hydrogen atom or anoptionally substituted alkyl, alkenyl or alkynyl group; R² represents anoptionally substituted alkyl alkenyl, alkynyl, cycloalkyl, aryl oraralkyl group; or R¹ and R² together with the interjacent nitrogen atomrepresent an optionally substituted aromatic heterocyclic group or anamino group derived from an optionally substituted amino acid ester. 28.The method of claim 27 in which Y represents a halogen atom.
 29. Themethod of claim 28 in which Y represents a fluorine atom.
 30. The methodof claim 27 in which Y represents a C₆₋₁₈ aryl group optionallysubstituted by one or more C₁₋₄ alkoxy substituents.
 31. The method ofclaim 30 in which Y represents a phenyl, dimethoxyphenyl, ortrimethoxyphenyl group.
 32. The method of claim 27 in which Y representsa group —NR¹R² where R¹ represents a hydrogen atom or a C₁₋₆ alkyl groupand R² represents a C₁₋₆ alkyl, C₆₋₁₀ aryl or C₇₋₁₆ aralkyl group, eachgroup being optionally substituted by one or more substituents selectedfrom the group consisting of halogen atoms and C₁₋₆ alkoxycarbonylgroups.
 33. The method of claim 32 in which Y represents a group —NR¹R²where R¹ represents a hydrogen atom or a C₁₋₄ alkyl group and R²represents a C₁₋₄ alkyl, phenyl or benzyl group, each group beingoptionally substituted by one or more substituents selected from thegroup consisting of halogen atoms and C₁₋₄ alkoxycarbonyl groups. 34.The method of claim 33 in which Y represents a propylamino,fluorophenylamino, benzylamino, phenylethylamino,phenyl-methoxycarbonylmethylamino, and diethylamino.